Chemistry
Chemical reactions, stoichiometry, molecular structures, and element properties.
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part of one row of the periodic table is shown. which elements atoms ha…
tellurium (Te)
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this is how krypton appears in the periodic table. rounded to the neare…
A. 36
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which is a precautionary measure? using a fire extinguisher to put out …
wearing safety goggles while mixing chemicals
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which two chemists organized elements based on properties such as how t…
B. Döbereiner and Newlands
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what happens to particles in matter when thermal energy is absorbed? th…
1. The average speed of the particles increases. 2. The upper particle diagram (with blue - white molecule pairs) represents a pure substance.
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in an elements square on the periodic table, the number with the greate…
atomic mass.
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what are 1a, 3b, and 7a examples of on the periodic table? o groups, o …
groups
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dmitri mendeleev and henry moseley developed their periodic tables abou…
The number of protons in an atom is different than the atom’s total mass.
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how many groups are in the modern periodic table? 12 18 22 24
B. 18
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chlorine is vital for safe drinking water and widely used in paper, tex…
Sodium
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the term route of entry on an sds refers to the way a ____ enters the b…
D. Chemical
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a skull and crossbones pictogram indicates this kind of information abo…
C. Acute Toxicity
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identifying the properties of platinum locate the element platinum (pt)…
Melting point: 1768.3 °C Boiling point: 3825 °C
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locate the element xenon (xe) on the periodic table and click on the sq…
noble gas
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a local reaction is when a chemical enters the bloodstream. true false …
False
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locate the element helium (he) on the periodic table. what is the perio…
What is the period number in which helium is found? 1 What is the group name in which helium is found? 8A
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identifying the properties of zinc locate the element zinc (zn) on the …
Protons: 30 Electrons: 30 Neutrons: 35
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visit the interactive periodic table and locate the element neon (ne). …
Atomic number: 10 Atomic mass: 20.2
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what is the name of the phase change represented by box d? condensation…
Freezing
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use the information in the square to answer the questions about copper.…
How many protons are in an atom of copper? 29 How many electrons are in an atom of copper? 29 How many neutrons are in an atom of copper? 35
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hazardous waste laws resource conservation and recovery act (rcra) ther…
preventing accidental releases of hazardous waste
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hazardous waste laws government entities hazardous waste is a global co…
B. Environmental Protection Agency (EPA)
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understand: physical properties, extrinsic & intrinsic ngss.ms: ms - ps…
- The first blank: physical property - The second blank: mass (or density, color, melting - point etc., any valid physical property)
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part a how many low dose 81 mg aspirin tablets can be made from 1.21 kg…
1.5×10^4 tablets
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part a how many microliters are in 41.0 ml? 41×10³ 4.10×10⁴ 0.041 41×10…
4.10×10⁴ μL (corresponding to the second option in the multiple - choice)
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using density as a conversion factor the following table displays prefi…
$4.71$
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which statements accurately describe trends found in the periodic table…
Henry Moseley established a periodic table that arranges the elements by atomic number. The atomic number increases from left to right on the periodic table. Metalloids have the c…
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aluminum has a density of 2.70 g/ml. calculate the mass (in grams) of a…
$983$
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part a using the relationship between mass and volume in density, deter…
| Given Value | Need | Conversion Factor | |--|--|--| | 50 g | mL of sample | $\frac{1\ mL}{X\ g}$ | | 55 mL | g of sample | $\frac{X\ g}{1\ mL}$ | | 45 L | kg of sample | $\frac{…
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q1 chemistry: u2l15 electron config day 5 as a laxative. the pill they …
1. No ideal answer for the "Everlasting Pill" from the given options. 2. Set 1 represents the correct pair of elements. Element A is sodium (Na) with electron - configuration 1s²2…
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q1 chemistry: u2l15 electron config day 5 teacher: date: name: as a lax…
Question 1: No correct answer among given options Question 4: Set 1 Question 5: Student B is correct.
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match each scientist with the contribution he made to the arrangement o…
Johann Wolfgang Döbereiner - created groups of three elements, each based on similar properties Antoine Lavoisier - divided elements into four categories Dmitri Mendeleev - used p…
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3 select the correct text in the passage. which phrases/sentences are t…
Primary colors cannot be obtained by mixing other colors. Mixing two primary colors gives you a secondary color. Mixing a primary color with an adjoining secondary color gives you…
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what is the name of the phase change represented by box b? freezing con…
Condensation
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what is a catalyst? a substance that speeds up a reaction a substance t…
A. A substance that speeds up a reaction
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why are yawns contagious? we asked a scientist by teresa carey there is…
to group together explanations to the same question
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there are several statements in the table below. for each, determine wh…
| Statement | Negation? (Yes/No) | |--|--| | I am in history class. | No | | I am not in chemistry class. | Yes | | I am not in physics class. | No | | It is not the case that I a…
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how is weight different from mass? weight changes depending on gravity,…
1. Weight changes depending on gravity, mass stays constant throughout the universe. 2. Reactants 3. Product
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question 5 of 8 prescription opioids share chemical similarities with h…
True
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3) look at the circles for each element, what happens as you move down …
# Explicación: ## Paso 1: Identificar números atómicos y masas atómicas Los números atómicos se representan por el subíndice y las masas atómicas por el superíndice en la notación…
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a chemist prepares a solution of iron(iii) bromide (febr₃) by measuring…
$3.7\times 10^{2}\ \frac{\mu mol}{L}$
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compound important species present when dissolved in water type of comp…
| compound | ionic | molecular | strong acid | weak acid | strong base | weak base | | ---- | ---- | ---- | ---- | ---- | ---- | ---- | | $HC_2H_3O_2$ | | $\checkmark$ | | $\check…
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compound important species present when dissolved in water type of comp…
| compound | important species present when dissolved in water | ionic | molecular | strong acid | weak acid | strong base | weak base | | ---- | ---- | ---- | ---- | ---- | ---- …
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predict the products of the reaction below. that is, complete the right…
$2HClO_4+Ca(OH)_2 ightarrow Ca(ClO_4)_2 + 2H_2O$
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classify each chemical compound listed in the table below. |compound|ty…
| compound | ionic | molecular | acid | base | |--|--|--|--|--| | Mg(ClO₄)₂ | √ | | | | | KOH | √ | | | √ | | H₃PO₃ | | √ | √ | | | HCl | | √ | √ | |
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a chemistry student weighs out 0.193 g of citric acid ($h_3c_6h_5o_7$),…
$17.7\ mL$
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6. the atom is electrically neutral because: a) protons = neutrons b) p…
6. b) Protons = Electrons 7. a) J.J. Thomson 8. b) Neutron 9. b) Rutherford
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4. which subatomic particle determines the identity of an element? a) n…
4. b) Proton 5. a) Protons + Neutrons
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name of the student: kamila cruz rodriguez date: 10/3/2025 1. who is kn…
1. b) John Dalton 2. c) Protons and Neutrons 3. b) -1
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question 11. a scientist is analyzing an element in the laboratory. the…
Mass Number = Number of Protons+Number of Neutrons Number of Neutrons = Mass Number - Number of Protons
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a chemist must prepare 525 ml of 1.00 m aqueous barium - chloride (bacl…
404 mL
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question 10. how many protons, electrons, and neutrons are in each atom…
| Atom | Number of Protons | Number of Electrons | Number of Neutrons | | ---- | ---- | ---- | ---- | | $_{32}^{73}\text{Ge}$ | 32 | 32 | 41 | | Osmium - 190 | 76 | 76 | 114 | | $…
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a chemist adds 1.25 l of a 0.16 mol/l potassium dichromate (k₂cr₂o₇) so…
$59\ g$
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pregunta 15 1 pts which of the following are ways that chemical element…
- Single atoms - Lattices - Clusters - Molecules
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pregunta 13 1 pts which of the following best explains why hydrogen can…
Pregunta 13: Hydrogen requires less potential energy to bond and Helium requires more. Pregunta 14: When the attraction between the nuclei and electrons is balanced with the repul…
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a chemist prepares a solution of nickel(ii) chloride (nicl₂) by measuri…
0.34 mol/L
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question 9. complete the table for the following elements. | element | …
| Element | Number of Protons | Number of Electrons | Number of Neutrons | Atomic Number | Mass Number | | --- | --- | --- | --- | --- | --- | | Manganese | 25 | 25 | 30 | 25 | 55…
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atoms that share electrons: have more valence electrons to attract. hav…
- Primera pregunta: have a more equal attraction to the electrons. - Segunda pregunta: low potential energy.
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calculate the volume in liters of a 0.237m potassium dichromate solutio…
$1.48$
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which of the following characteristics best determines whether atoms sh…
The amount of attraction between the positive charge of the nuclei and the electrons.
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a chemist adds 0.25 l of a 5.30m sodium nitrate (nano₃) solution to a r…
$1.3$
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b. converting number of particles to moles n = n / nₐ (nₐ ≈ 6.02×10²³) …
1. $9.7\text{ mol}$ 2. $0.141\text{ mol}$ 3. $12.8\text{ mol}$
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question 8. match the labels to the correct part of the atomic symbols …
From left to right for nuclear notation: Atomic number, Element symbol, Mass number. For hyphen notation: Element name, Mass number.
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pregunta 8 1 pts bonds are more likely to be broken and formed: in bigg…
# Breve explicación: La energía térmica ayuda a romper y formar enlaces químicos. A temperaturas más altas, las moléculas tienen más energía cinética, lo que las hace más propensa…
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a chemist prepares a solution of sodium hyposulfate (na₂s₂o₃) by measur…
$684\ \mu\text{mol/L}$
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pregunta 7 1 pts why are the number of valence electrons more important…
- Valence electrons determine the reactivity of an atom. - Valence electrons are the number of electrons that an element has available for bonding.
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question 7. complete the table showing the number of protons and electr…
| Element Name | Element Symbol | Atomic Number | Number of Protons | Number of Electrons | | ---- | ---- | ---- | ---- | ---- | | Hydrogen | H | 1 | 1 | 1 | | Helium | He | 2 | 2…
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question 6. why is an atom electrically neutral? what does the atomic n…
An atom is electrically neutral because the number of protons equals the number of electrons. The atomic number of an atom represents the number of protons in the nucleus of the a…
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pregunta 6 the periodic table can be used to predict the number of vale…
# Breve explicación: Los elementos en el mismo grupo de la tabla periódica tienen el mismo número de electrones de valencia. El período se asocia con el número de niveles de energ…
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question 5. how many neutrons does a beryllium atom with four protons a…
5
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which of the following describes valence electrons? the electrons in an…
# Breve explicación: Los electrones de valencia son los electrones ubicados en el nivel de energía más externo o "capa" de un átomo. Estos electrones son los que participan en las…
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question 4. what is the mass number of a helium atom that has two proto…
4
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dante owned land that was found to be rich in aluminum. he investigated…
The aluminum is bonded to other elements in the rock.
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question 3. the total number of protons and neutrons in an atom is its
Mass - number
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question 2. the element nitrogen (n) has an atomic number of 7. how man…
Number of Protons = 7 Number of Electrons = 7
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gaseous butane (ch₃(ch₂)₂ch₃) reacts with gaseous oxygen gas (o₂) to pr…
$61.0\%$
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question 1. elements are different because their atoms contain differen…
protons.
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pregunta 1 1 pts atoms of elements in nature exist mostly by themselves…
- Pregunta 1: mostly in combination with other atoms in a molecule or compound - Pregunta 2: Because electrons are electrically attracted to the nucleus
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which of the following is the correct lewis dot structure for a barium …
[Ba]^{2 + } (la segunda opción en la imagen proporcionada)
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part 2: finding elements for symbols element symbol ge k v no in p as a…
Germanium Potassium Vanadium Nobelium Indium Phosphorus Arsenic Astatine Zirconium Lawrencium
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which of the following is the correct lewis dot structure for an alumin…
# Explicación breve: El aluminio (Al) es un metal del grupo 13. Tiene 3 electrones de valencia. Para cumplir con la regla del octeto, pierde sus 3 electrones de valencia y se conv…
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4. how many particles are in 1.20 mol of sodium sulfide? n = ? n = 1.20…
5. $7.525\times 10^{23}$ particles 6. $1.07156\times 10^{22}$ atoms 7. $1.2642\times 10^{23}$ formula - units 8. $3.34712\times 10^{25}$ molecules 9. $1.505\times 10^{24}$ molecul…
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which of the following is the correct lewis dot structure for a neutral…
# Explicación: ## Paso 1: Encontrar el número de electrones de valencia El cloro tiene 7 electrones de valencia. ## Paso 2: Representar en estructura de Lewis Se representan los e…
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suppose 1.5 g of compound a are consumed in a reaction with 4.0 g of co…
5.5 g 55%
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element symbol xenon barium platinum fluorine argon tungsten magnesium …
xenon: Xe barium: Ba platinum: Pt fluorine: F argon: Ar tungsten: W manganese: Mn silver: Ag radium: Ra
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aqueous hydrobromic acid (hbr) will react with solid sodium hydroxide (…
$35\ g$
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use the periodic table in your textbook part 1: finding symbols for ele…
| ELEMENT | SYMBOL | | ---- | ---- | | copper | Cu | | lithium | Li | | silicon | Si | | zinc | Zn | | thorium | Th | | krypton | Kr | | tin | Sn | | bismuth | Bi | | boron | B | …
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acetylene (c₂h₂) gas and oxygen (o₂) gas react to form carbon dioxide (…
$12.6$
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multiple - choice question in a water molecule, atoms of hydrogen and o…
A. False
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green plants use light from the sun to drive photosynthesis. photosynth…
$10.9\text{ g}$
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multiple - choice question oxygen bonds help hold water molecules toget…
False
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not including water, states of matter generally follow the rule(s) belo…
Solid matter is more dense than liquid matter of the same chemical formula. Liquid matter is more dense than gaseous matter of the same chemical formula. Solid matter is more dens…
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in a water molecule, atoms of hydrogen and oxygen are positively charge…
False
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down 1. most active nonmetals 2. group ii metals 3. the atomic number i…
1. Halogens 2. Alkaline earth metals 3. Protons 7. Positive 9. Number 11. Groups
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the movie below shows some molecules in a tiny sample of a mixture of g…
$Cl_2 + H_2 ightarrow2HCl$
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solid magnesium reacts with aqueous iron(iii) chloride to form aqueous …
3Mg(s)+2FeCl₃(aq) → 3MgCl₂(aq)+2Fe(s)
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chlorine gas reacts with solid phosphorus to form phosphorus trichlorid…
$2P(s)+3Cl_2(g) ightarrow 2PCl_3(g)$
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use the periodic table in your textbook to fill in the missing informat…
See the above - filled table for element - symbol correspondences.
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subatomic particles worksheet (fill in the missing information) element…
| Element | Atomic # | Atomic mass | \(\#p^{+}\) | \(\#e^{-}\) | \(\#n^{0}\) | | ---- | ---- | ---- | ---- | ---- | ---- | | magnesium | 12 | 24 | 12 | 12 | 12 | | argon | 18 | 40…
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activity of the elements since metals prefer to give away electrons dur…
1. Na 2. F₂ 3. N 4. Rb 5. Ca 6. K 7. O₂ 8. Br₂ 9. Na 10. S 11. O₂ 12. Cl₂ 13. Fr 14. Rb 15. Cr 16. Cl₂ 17. I₂ 18. Ra 19. Sr 20. K 21. Mg 22. S 23. Li 24. Br₂ 25. F₂ 26. Rb 27. Ra …