化學
化學反應、化學計量、分子結構與元素性質。
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reference the conversion below to determine how many liters are in 10.0…
9.46 L
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mass number → a (n of protons + n of neutrons) x element atomic number …
Isotope: Same number of $\boldsymbol{\text{protons}}$ and $\boldsymbol{\text{electrons}}$ (in neutral), different number of $\boldsymbol{\text{neutrons}}$. Ions: Same number of $\…
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dress the part in the laboratory a scientist works in a ________. labor…
1. A scientist works in a **laboratory**. Laboratories are where scientists run **experiments** instead of their **opinions** and make most of their observations, measurements and…
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age of science 1747 andraeas marggraf discovers that beet sugar is iden…
B. It documents key events in the sugar and sweetener industries.
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what happens if you heat a diamond to 1,405°f?
it
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6 organize the steps in this experiment according to the scientific met…
To solve this, we follow the scientific method steps: observation, question, hypothesis, experiment, data collection, conclusion. ### Step 1: Observation The first step in the sci…
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6 organize the steps in this experiment according to the scientific met…
To solve this, we follow the scientific method steps: observation, question, hypothesis, experiment, data collection, conclusion. ### Step 1: Observation The first step in the sci…
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choose all that are correct. a neutron... ...has a mass of 1 gram. ...h…
-...has a mass of 1 amu. -...is located in the nucleus. -...has no charge.
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6. a piece of metal has a volume of 30.0 cm³ and a mass of 252 g. what …
The density is $8.4\ \text{g/cm}^3$, and the metal is likely brass (or a similar metal with a density around this value).
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property physical or chemical? melting point of 1,538°c rusts in the pr…
s (from top to bottom): 1. Physical 2. Chemical 3. Physical 4. Physical
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which statement best supports your claim? choose 1 answer: a the sulfur…
B. New bonds form between rubber molecules and sulfur. This creates a substance with different properties.
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using the information in the table above, make a clai vulcanizing rubbe…
chemical
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which of the following indicate that a chemical change likely occurred?…
C. bubble formation from a new gas, D. light and heat production
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which statement best describes what happens during a chemical change? c…
B. The identity of the original substance changes.
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complete the statement. a chemical property is a characteristic of a su…
C. describes how a substance behaves in a chemical change
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• an example of a chemical property is related content chemical changes…
flammability
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complete the following statements. • the chemical properties of a subst…
- The chemical properties of a substance can be observed $\boldsymbol{\text{only by}}$ changing the identity of a substance. - An example of a chemical property is $\boldsymbol{\t…
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chemotherapy and radiation is used to treat which disease? a. schizophr…
B. Cancer
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which of the following is not an example of a chemical property? choose…
C. Iron is magnetic.
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in the second column, write the name of each whmis symbol. then choose …
1. Name of the symbol: Corrosive; What the symbol means: Will corrode substances with which it comes in contact, including human flesh 2. Name of the symbol: Health Hazard; What t…
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what is the atomic number of mg²⁺? a 12 b 24 c 25 d 55 question 28 what…
A. 12 ### Second Question (Atomic number of $\boldsymbol{\ce{Na^{+}}}$)
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isotopes of an element always have the same a mass number b number of n…
D. Atomic number ### Question 39 (Atomic structure formula)
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page 2 – states of matter matter exists in different forms called state…
The three most common states of matter are solid, liquid, and gas. In a solid, particles are packed tightly together and have a definite shape and volume. In a liquid, particles a…
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question 2 a researcher combines three liquid samples with the volumes …
The total volume of liquid the researcher has is approximately \(2.54\space L\) (or more precisely \(2.537205\space L\)) after converting all volumes to liters and summing them: \…
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page 3 – atoms & elements all matter is made of tiny particles called _…
1. atoms 2. nucleus; protons; neutrons 3. electrons 4. atom; atom 5. elements; hydrogen; oxygen 6. physically; chemically combined; homogeneous; heterogeneous
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what is rhyme scheme? (1 point) several words in a short section beginn…
B. the pattern of rhyming words at the end of each line in a poem
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which of the following solutions uses sugar as the base and tends to be…
B. Syrup
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use the stanzas to answer the question. what is the rhyme scheme of the…
D. abbabb (assuming the last option is D; if the options are labeled as A: abcabc, B: abccba, C: abaaba, D: abbabb, then the answer is D. abbabb)
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lab safety n c l e a n u p s h r e n m p f r b z n q l e p l a c s t d …
The subfield for this lab safety - related problem is Natural Science: Biology, Chemistry, Physics, Medicine and Health, Nursing, Geography, Engineering, Computer Science, Environ…
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which piece of text uses this definition of promotion? promotion (noun)…
Naomi works for an organization that is dedicated to the promotion of math and science education for girls. She runs a summer camp that teaches girls about chemistry and engineeri…
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which of these are fundamentally electric potential energy, when consid…
A. chemical potential energy, C. elastic potential energy
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tablet 25 water 10 baggie 4 total 39\ttotal 38 matt and juan are studyi…
D. Some gas escaped from the baggie before the boys had it completely closed
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19. explain how temperature affects the rate of sugar dissolving in wat…
Higher temperature increases the rate of sugar dissolving in water by increasing molecular kinetic energy (more frequent, energetic collisions); lower temperature decreases the ra…
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tablet 25 water 10 baggie 4 total 39\ttotal 38 matt and juan are studyi…
C. Some of the water evaporated and could not be massed as a product in the reaction
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18. how many atoms total are in the formula nacl?
2
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chemical and physical changes part b while studying chemical and physic…
D (assuming the full option D states: "No, it is a physical change. A chemical change forms a new substance, but dissolving salt only mixes it with water; the salt can be recovere…
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chemical and physical changes 1. images: i (pipes exposed to air for si…
D. The pipes in image I are going through a chemical change called rusting; the evidence is the color change
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17. identify whether each is a physical or chemical change: a. ice melt…
a. Ice melting: Physical change ### Part b: Wood burning
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16. true or false: hcl is a compound.
True
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i. a chemical change breaks bonds, forms new substances and is irrevers…
A. I & III
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15. match each method to its effect: a. stirring b. heating c. crushing…
a. Stirring - 2. Moves solute around faster b. Heating - 1. Adds energy to particles c. Crushing - 3. Increases surface area
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color change formation of a gas temperature change density melting poin…
A. flammability
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which of the following guidelines should a pharmacy technician consider…
B. Use the smallest device that will accommodate the liquid. ### Second Question (Disposal in Normal Trash) (Note: Since the options are partially visible, we assume based on phar…
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12. is lemonade a solution? explain.
Yes, lemonade is a solution. It is a homogeneous mixture where solutes (e.g., sugar, lemon juice components) are dissolved in a solvent (water), resulting in a uniform composition…
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picture d represents the only possible option as the correct products. …
D. Picture D rearranges the atoms whereas A, B, and C did not
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9. which of the following tables represents data that have a proportion…
B ### Question 10
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11. what happens to concentration if you add more water to a sugary dri…
When more water is added to a sugary drink, the concentration of the sugar (solute) in the drink (solution) decreases (the drink becomes more diluted).
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sara is making an omelet. she cracks open 6 eggs and places them in a b…
A. cutting pepper, B. cutting onion, D. mixing eggs
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10. in a saltwater solution, which is the solute? which is the solvent?
Solute: Salt (sodium chloride, \( \text{NaCl} \)) Solvent: Water (\( \text{H}_2\text{O} \))
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chunk 1: tom and the fence tom appeared on the sidewalk with a bucket o…
The mood is gloomy and burdensome. The author creates it by describing Tom's feelings (life hollow, existence a burden) and his task (whitewashing, a chore), using somber language…
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10. in a saltwater solution, which is the solute? which is the solvent?…
Solute: Salt (Sodium Chloride, \( \text{NaCl} \)) Solvent: Water (\( \text{H}_2\text{O} \)) ### Question 11:
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3. fill in the blank: an element is made of only one kind of blank. 4. …
atom ### Question 4
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atomic structure worksheet fill in the blanks for the elements in this …
To solve the atomic structure worksheet, we use the following concepts: - **Atomic Number (Z)** = Number of Protons = Number of Electrons (in a neutral atom). - **Atomic Mass (A)*…
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in your lab group you combined vinegar and baking soda and observed the…
A. A gas is produced, C. Bubbling occurred, E. There is a change in the composition of the reactants
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chemical and physical properties which image(s) shows a physical proper…
A. I, B. II, C. III
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1. compare a molecule of oxygen (o₂) and a molecule of water (h₂o) 2. w…
B) \(CO_2\) ### Question 3
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examine the image and assess the relationship of the atoms shown by: ch…
A. The rearrangement of atoms is a chemical change.
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5. which compound is used as an antacid to neutralize excess stomach ac…
c) $\ce{Mg(OH)_{2}}$
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8. give the symbol and number of electrons in a neutral atom of: uraniu…
### Question 8 To solve for the symbol and number of electrons in a neutral atom, we use the fact that in a neutral atom, the number of electrons equals the number of protons (ato…
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d) phenacetin 3. which artificial sweetener is used by diabetic patient…
a) Saccharin ### Question 4
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prepare for lab - always use ________ in the lab. - handle chemicals __…
This worksheet is about lab safety, which falls under the Natural Science discipline, specifically in the subfield of a general lab safety context (related to experimental science…
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1. which chemical is commonly used in toothpaste to prevent tooth decay…
c) Fluoride compounds ### Question 2
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barbara completed an assignment for extra credit in science class. she …
A. to the left of cola
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1. an example of a physical property is ______ a. flammability b. abili…
d. State of matter ### Question 2
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question 1 points 1 ______ is rarely found in a gaseous state. phosphor…
B. Carbon
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16. draw the lewis dot structure for each of the elements and identify …
| ATOM | Lewis Dot Structures | # of lone pairs | # of bonding electrons | |----------|----------------------------|-----------------|------------------------| | bromine | \(\cdot…
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7. __ hcn + __ cuso₄ → __ h₂so₄ + __ cu(cn)₂ 8. __ gaf₃ + __ cs → __ cs…
Let's solve these chemical equations by balancing them one by one. We'll use the method of balancing atoms on both sides of the equation. ### Problem 13: $\boldsymbol{AlBr_3 + K_2…
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layers of the earth chemical layers - physical layers what layer drives…
### 1. Chemical Layers of Earth The Earth’s chemical layers are based on **composition**: - **Crust**: Outermost, thin layer (continental: granite, oceanic: basalt). - **Mantle**:…
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cambridge pre-aice french language 2 igcse level - carder - p01 - s01 k…
**A. une casquette ### Question 4 (assuming "identify feminine noun"): - *une jupe* (feminine, "a skirt") - *un chemisier* (masculine, "a blouse/shirt") - *une chaussure* (feminin…
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scr (answer with ~30 words / 2-3 sentences) 1. how can you tell the dif…
Un cambio químico forma una nueva sustancia (ej: oxidación), mientras que un cambio físico mantiene la sustancia original (ej: fusión).
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drawing prompts 1. draw a before-and-after picture of a nail rusting. l…
To draw the before - and - after of a nail rusting (chemical change): - **Before**: Sketch a shiny, smooth iron nail (label: "Before - Iron Nail (Fe)"). - **After**: Sketch the na…
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4. why is baking a cake considered a chemical change? a) the cake batte…
b) A new substance with new properties is formed
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1.the 3 particles of the atom are: a. b. c. their respective charges ar…
a. Proton b. Neutron c. Electron Their respective charges are: a. Positive (+) b. Neutral (no charge) c. Negative (-) ### Question 2
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in chemistry, logarithms are key to calculating the ph of a solution. i…
D. \( H^+ = 10^{-2.6} \) (and also C. \( H^+ \approx 10^{-3} \) is a reasonable approximation, but the exact answer from the formula is \( H^+ = 10^{-2.6} \)) Wait, the options ar…
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3. what type of change in matter happens when your body breaks down the…
b) chemical change
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2. which is not a characteristic of chemical changes in matter? a) ligh…
b) The matter remains unchanged
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aice french language 2 igcse level - carder - p01 - s01 > launch vhlcen…
To solve this fill - in - the - blank exercise in French, we analyze the context and the meaning of each word: ### (2) Maria is looking for a piece of clothing. Among the options,…
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multiple choice questions 1. what is a characteristic of a physical cha…
b) The composition is unchanged
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practice: balancing equations #2 show all work on a separate sheet of p…
The balanced equation is \( \boldsymbol{1}\text{Pb(OH)}_2 + \boldsymbol{2}\text{HCl} ightarrow \boldsymbol{2}\text{H}_2\text{O} + \boldsymbol{1}\text{PbCl}_2 \) (coefficients: 1, …
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a student wants to conduct an investigation that will determine a physi…
D. 1. Place the sample in a resealable, zip - top bag; 2. Firmly close the zip - top bag; 3. Lightly tap the sample with a hammer; 4. Observe if the sample dents, breaks, or shatt…
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1. djamila veut acheter (1) blank pour aller à la plage en côte dazur, …
(1) un maillot de bain (2) soldes (3) couleurs (4) chers (5) chemisier (6) une jupe (7) un maillot de bain (8) une vendeuse
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the law of conservation of mass tells us that the total number of atoms…
A. \( 4NH_3 + 5O_2 ightarrow 4NO + 6H_2O \) B. \( 8H_2S + 8Cl_2 ightarrow S_8 + 16HCl \) E. \( 2Al(OH)_3 + 3H_2SO_4 ightarrow Al_2(SO_4)_3 + 6H_2O \)
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a flask with vinegar in it has a mass of 160 grams. a balloon with baki…
B. 200 grams, because all the atoms remain in the balloon or flask.
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sulfuryl chloride is a substance used to make chemicals for killing ins…
### Part 1: Completing the table (for O, S, Cl atoms) #### Step 1: Analyze Oxygen (O) atoms - From \( SO_2 \): Each \( SO_2 \) has 2 O atoms, and there are 2 \( SO_2 \) molecules.…
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hydrogen peroxide can be used to disinfect and clean surfaces around th…
s: - Number of H atoms: \( 12 \) - Number of O atoms: \( 12 \) - Number of H₂O₂ molecules: \( 6 \)
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sulfur dioxide is a gas released when volcanoes erupt. it can react wit…
- O atoms: \(24\) - S atoms: \(8\) - \(SO_3\) molecules: \(8\)
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acetaldehyde is a substance commonly used in chemical factories. it is …
### Part 1: Completing the table (number of atoms) #### For Hydrogen (H): ## Step1: Calculate H from $C_2H_4$ Each $C_2H_4$ has 4 H atoms. There are 4 molecules of $C_2H_4$. So to…
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properties of atoms and compounds 1 can be solids, liquids or gases at …
2, 4, 6, 7
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in the atmosphere, nitric oxide forms when a lightning strike causes ni…
s: - Number of N atoms: \( 6 \) - Number of O atoms: \( 6 \) - Number of NO molecules: \( 6 \)
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ammonia is commonly used as a fertilizer for plants. it is made when ni…
s: - Number of H atoms: \( \boldsymbol{18} \) - Number of N atoms: \( \boldsymbol{6} \) - Number of \( \text{NH}_3 \) molecules: \( \boldsymbol{6} \)
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the number of protons in an atom is known as its atomic number. atoms t…
3 ### Second Sub - Question: Which of the following models also represents a lithium atom? (Note: Since the specific models' details are not fully visible in text, but based on th…
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below are two atomic models. each model represents a different atom. at…
electrons
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13. label the following statements describing: 1 ionic bonds 2 covalent…
2 1 1 2
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study the following phase diagram of substance x. use this diagram to a…
s: 1. For the first sub - question: The state of the sample is liquid. 2. For the second sub - question: The sample will vaporize (boil) (liquid→gas). 3. For the third sub - quest…
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rank the elements or compounds in the table below in decreasing order o…
1. B. HgCl₂ 2. A. H₂O₂ (Lewis structure H-O-O-H) 3. C. HCl 4. D. H₂ (already set as 4) (For the dropdowns: Highest boiling point is B (HgCl₂), next is A (H₂O₂), then C (HCl), then…
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9. directions drag and drop the correct answer choice to each answer bl…
The student thinks a chemical change is occurring because when the two solutions mix, the student observes a unexpected change in \boxed{color}. Therefore, the student claims that…
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question 11 of 20 : select the best answer for the question. 11. the va…
A. equal to the number of positive or negative charges on the ion.
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question 14 of 20 : select the best answer for the question. 14. regard…
D. The subscript 2 indicates that two atoms of aluminum are present in the substance.
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look at the chemical reaction. magnesium + hydrochloric acid → magnesiu…
- Magnesium ($\ce{Mg}$): Reactant - Hydrogen ($\ce{H_{2}}$): Product - Magnesium chloride ($\ce{MgCl_{2}}$): Product - Hydrochloric acid ($\ce{HCl}$): Reactant
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look at the chemical reaction. ammonium hydroxide → ammonia + water nh₄…
- Ammonia ($\ce{NH_{3}}$) is a **product** - Ammonium hydroxide ($\ce{NH_{4}OH}$) is a **reactant (or decomposing substance)**