Química
Reacciones químicas, estequiometría, estructuras moleculares y propiedades.
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which element will form an ionic bond with potassium, k? rubidium, rb b…
Sulfur, S
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at what state of energy do atoms form bonds? a high energy state energy…
a low energy state
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each of these atoms are in group 2. which atom will have the smallest a…
Beryllium, Be (2 energy levels)
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which of these is a transition metal? potassium, k strontium, sr tungst…
tungsten, W
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identifying elements use the periodic table to identify the marked elem…
non - metal
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which element has 79 protons? rhodium, rh gold, au selenium, se scandiu…
gold, Au
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using the bohr model, find the correct isotope notation for oxygen.
The third option \( _{8}^{16}O \) is correct.
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use this information to write the isotope notation for an element with …
\(_{16}^{32}S\)
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using the element tiles, what element has 35 protons? na cl br
Br
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where is a neutron located within the atom? in the proton cloud in the …
in the nucleus
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what does this model represent? an atom a compound a diatomic element
an atom
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which of the following is an atom? n ch₄ hcn
N
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what type of symbolic representation is shown below? $delta t = t_f - t…
Mathematic Relationship
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which particle model represents sugar dissolving in water?
The third particle model.
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the chemical element, silver, boils at a temperature of 3,924 degrees f…
\(2162.2\)
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what are the freezing and boiling points of water? 0°c and 32°f 0°c and…
B. \(0^\circ \text{C}\) and \(212^\circ \text{F}\) (assuming the options are labeled as A, B, C, D, E with the second option being B; if the original options had different labels,…
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in science class, richard learns that petrol has a boiling point of 203…
\(95^{\circ}\text{C}\) (corresponding to the option \(95^{\circ}\text{C}\))
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a scientist wants to measure out 0.62 liters of a liquid, but she can o…
A. 620 milliliters
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the periodic table and periodic law reviewing vocabulary match each def…
1. j. periodic law 2. k. representative elements 3. l. transition elements 4. a. alkali metals 5. b. alkaline earth metals 6. m. group 7. e. period 8. d. halogens 9. h. noble gase…
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what is the boiling point of water? 0°c and 32°f 32°c and 100°f 100°c a…
C. \(100^\circ \text{C}\) and \(212^\circ \text{F}\)
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in science class, richard learns that a substance has a melting point o…
150°C (corresponding to the option "150°C")
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the movement of the progress bar may be uneven because questions can be…
- Boiling Point Fahrenheit: 212 - Freezing Point Fahrenheit: 32 - Boiling Point Celsius: 100 - Freezing Point Celsius: 0 (Note: The 273 in the options is the Kelvin temperature fo…
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mole practice 1. you have exactly 6.022 * 10^{24} atoms of iron on your…
\(10\space mol\)
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identify the following reactions as formation, simple decomposition or …
| Reaction | Classification | |--|--| | \(2H_2O_2(l)\to2H_2O(l)+O_2(g)\) | simple decomposition | | \(NH_3(g)+H_2O(l)\to NH_4OH(aq)\) | formation | | \(Fe(s)+\frac{1}{2}O_2(g)\to …
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stara helps her father install an air purifier in her house. what type …
B. filtration
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fill in a word that correctly completes the sentence. martina is campin…
chemical
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marina is camping and needs wood for a cooking fire as well as for shel…
B. a change in physical property
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4. classify think about different mixtures that are in a kitchen. name …
- Homogeneous mixtures: Vinegar (acetic acid in water, uniform composition), Brine (salt - water solution, uniform composition). - Heterogeneous mixtures: Salad dressing (oil and …
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given the following data: enthalpy of formation for various nitrogen ox…
159
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use the following information to answer the next question. given the fo…
-64
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given the following data: $p_{4}(s)+6cl_{2}(g)\\to4pcl_{3}(g)$ $\\delta…
\(249.75\)
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8. what indicators can you use to determine if a substance is acidic or…
Here is a filled table with two common indicators: | Indicator | When put in Acid | When put in Base | |-----------|------------------|------------------| | Litmus (Blue) | Turns …
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1 the height of water in a bathtub, w, is a function of time, t. let p …
\( A \)-2, \( B \)-4, \( C \)-3, \( D \)-1 ### Problem 2 #### Part (a)
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13. this is one - half the distance from the nucleus of the atom to the…
13. D. atomic radius 14. B. frequency 15. C. valence electron 16. D. F 17. A. Cs
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part 1 multiple choice: select the letter choice that best answers the …
1. B. contains nearly all of the atom's mass. 2. D. speed 3. C. Coulomb's Law 4. B. ionization energy 5. C. lost; positive 6. D. all the above 7. B. gained; negative 8. C. smaller…
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what is the empirical formula of this compound? h₂o₂ ho h₂o h₄o₄
HO
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final test question: 17 a food worker has finished cutting raw chicken …
a. Wash hands and change gloves
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what is the percent al in al₂o₃? (al = 26.98 g/mol, o = 16.00 g/mol) % …
52.92%
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how many moles of nacl are in 120 g nacl? assume 1.0 mol nacl = 58 g \\…
2.1 mol
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what is a requirement for storing chemicals? a. chemical containers sho…
A. Chemical containers should be clearly labeled
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what is the molar mass of this compound? kmno₄ remember to round to the…
158.04 g/mol
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how many chromium atoms are present in one mole of sodium chromate? na₂…
6.0 x 10²³ atoms
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how many chromium atoms are present in one formula unit of sodium chrom…
1 atom
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how many atoms are present in 2.0 moles na? 2.0 moles na 1.2 x 10^{24} …
1.2 x 10²⁴ atoms Na
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try: for each pair of compounds: circle the compound of each pair that …
a. NaCl; b. \(H_2O\); c. \(CO\)
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balance the chemical reaction below. c + 2f₂ → ? cf₄ when the equation …
1
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balance the chemical reaction below. c + ?f₂ → cf₄ when the equation is…
2
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balance the chemical reaction below. ?c + f₂ → cf₄ when the equation is…
1
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which is the most important reason to use contraception? o to delay bec…
B. to prevent an unintended pregnancy
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chem 20 - stoichiometry check in (d1/d2a) nov 7th please show your work…
1.25 moles ### Part (b)
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use the diagram below to answer the following question. what phase chan…
condensation
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water & carbon worksheet instructions: answer the following questions. …
Ice has a rigid, hexagonal lattice structure due to hydrogen bonds. This structure has more empty space than liquid water. As density ($ ho=\frac{m}{V}$) depends on volume ($V$) f…
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m = \\frac{26.18\\ mol\\ nacl}{990.1\\ l\\ sol^n}
The molarity \( M \) is approximately \( 0.02644\space\text{mol/L} \) (or \( 0.02644\space M \)).
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because an achiral molecule is symmetrical, flipping it yields a struct…
C. by contrast,
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1.53×10³ nacl × \\frac{1mol}{58.45g}
The number of moles of \( NaCl \) is approximately \( 26.2\, \text{mol} \) (or more precisely \( \approx26.18\, \text{mol} \))
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you have a 1.53×10³ ppm solution. what is the concentration in molarity…
The molarity of the NaCl solution is approximately $\boxed{0.0264 \, M}$ (or more precisely, around 0.0264 mol/L).
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match the correct bohr model to its element. boron chlorine magnesium p…
Boron - B, Chlorine - C, Magnesium - A, Potassium - D
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which diagram is the correct electron dot diagram for the element bromi…
G.
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which diagram is the correct electron dot diagram for the element heliu…
D.
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describe air phenomena and properties what properties can we use to des…
### Properties of Air: Air is a gas with properties like occupying space (e.g., it fills a container), having weight (gravity acts on its molecules), exerting pressure (molecules …
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what can a person do to limit exposure to x - rays? wear sunblock avoid…
wear a protective lead vest
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many of the gaseous elements form diatomic molecules. figure 1: masses …
To solve for the molar mass (slope) of each substance, we use the slope formula \( \text{slope} = \frac{y_2 - y_1}{x_2 - x_1} \), where \( y \) is mass (g) and \( x \) is amount (…
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question 6 1 pts what is thermal energy? energy from sound the movement…
C. heat
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question 5 how is all energy connected? as it constantly moves from pla…
A. As it constantly moves from place to place
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question 3 what is chemical energy? the movement of electrons throughou…
B. The potential energy in chemical compounds that is waiting to be released
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question 1 what is the possible or stored energy in an object called? k…
C. potential energy
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q.3. identify the following elements as metals, nonmetals, or metalloid…
Hydrogen (H): nonmetal Helium (He): nonmetal Lithium (Li): metal Boron (B): metalloid Oxygen (O): nonmetal Aluminum (Al): metal Silicon (Si): metalloid Chlorine (Cl): nonmetal Cal…
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a.) identify the names of the described phase changes. you must correct…
- Gas to liquid: Condensation - Solid to liquid: Melting - Liquid to solid: Freezing - Liquid to gas: Vaporization (or Boiling) - Solid to gas: Sublimation - Gas to solid: Deposit…
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use our demonstrations and discussions from last class to developed a r…
### Inputs: Gasoline, Air ### Matter Change: Combustion (hydrocarbon + $\ce{O_2}$ → $\ce{CO_2 + H_2O}$) and piston - crankshaft motion ### Energy - Matter Connection: Chemical (co…
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slide 5 balance a chemical equation balance the chemical equation for t…
Reactants: - Carbon (C) = \( \boldsymbol{2} \) - Oxygen (O) = \( \boldsymbol{7} \) - Hydrogen (H) = \( \boldsymbol{6} \) Products: - Carbon (C) = \( \boldsymbol{2} \) - Oxygen (O)…
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balance a chemical equation balance the chemical equation for the chemi…
The balanced equation is \( \boldsymbol{1} \, C_2H_5OH + \boldsymbol{3} \, O_2 ightarrow \boldsymbol{2} \, CO_2 + \boldsymbol{3} \, H_2O \) Atom counts: - Reactant (C₂H₅OH + O₂): …
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nov 24 app.nearpod.com view n₂ + h₂ → nh₃
The balanced equation is \( \text{N}_2 + 3\text{H}_2 ightarrow 2\text{NH}_3 \), so the coefficients are 1 (for \( \text{N}_2 \)), 3 (for \( \text{H}_2 \)), and 2 (for \( \text{NH}…
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what happens to the matter when fuel burns? how does the addition of bt…
### What happens to the matter when fuel burns? When fuel (e.g., ethanol) burns, it undergoes **combustion** (a chemical reaction). The fuel (containing carbon, hydrogen, etc.) re…
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what happens to the matter when fuel burns (genie in the bot what made …
The flame goes out quickly due to lack of oxygen (from a confined space) or rapid fuel burning. Matter inputs are fuel (e.g., ethanol) and oxygen; outputs are \(CO_2\), \(H_2O\), …
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matter inputs ... what about in a gasoline - powered vehicle? what is y…
Similarities between ethanol and gasoline include: - Both contain carbon and hydrogen atoms (organic compounds). - Both are used as fuels in internal combustion engines (e.g., in …
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what are the matter inputs and outputs when we burned the ethanol? what…
- **Matter Inputs**: Ethanol (\(C_2H_5OH\)) and oxygen (\(O_2\)) (from the surrounding air). - **Matter Outputs**: Carbon dioxide (\(CO_2\)) and water (\(H_2O\)) (released as gas …
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what pollutant causes an increase in algal growth? nutrients coming fro…
nutrients coming from fertilizers
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experience 3 review questions 1. what happens to electrons in an atom w…
1. They move from lower to higher energy levels (become excited). 2. The set of discrete wavelengths of light emitted by excited atoms as electrons transition to lower energy leve…
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this is an octane molecule ( found in gasoline). what do you notice abo…
- Notice about gasoline molecules: Gasoline molecules (e.g., octane) are hydrocarbons, primarily composed of carbon and hydrogen atoms, often arranged in long (or branched) carbon…
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how could we use this equipment to gather data to identify matter chang…
### First Sub - Question (Lab Design) 1. Setup: Put the empty tea candle holder in the beaker and add ethanol to the holder. 2. Ignition: Use the piezo igniter to light the ethano…
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share (turn & talk) what matter changes are occurring inside the system…
### Matter Changes: - **Inside the car**: Chemical change (fuel combustion in engine, new substances like \( \ce{CO_2} \) and \( \ce{H_2O} \) formed); physical changes (coolant va…
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a chemist has a sample of radioactive material. he records the amount o…
36
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true/false? increasing the temperature is the most obvious way to incre…
True
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examples of energy transfers include collisions in chemical and nuclear…
True
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at higher temperatures, why will diffusion happen faster?
At higher temperatures, particles (atoms, molecules, or ions) have more kinetic energy. This increased kinetic energy makes them move faster and more randomly. As a result, the ra…
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balance the following equations 11. cu + agno3 → cu(no3)2 + ag 12. …
11. \(1Cu + 2AgNO_3 ightarrow 1Cu(NO_3)_2+2Ag\) 12. \(2(NH_4)_3PO_4 + 3Ba(OH)_2 ightarrow 1Ba_3(PO_4)_2+6NH_4OH\) 13. \(4NH_3+3O_2 ightarrow 2N_2 + 6H_2O\) 14. \(39.10\space g/mol…
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in the diagrams given on the left, from which side to which side will t…
Left to the right (assuming the left side has a higher concentration of particles initially, as diffusion occurs from an area of higher concentration to lower concentration to ach…
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7. what are the properties of acids and bases? acid properties base pro…
| Acid Properties | Base Properties | |-----------------|-----------------| | - Sour taste <br> - React with metals (produce H₂) <br> - Turn litmus red <br> - React with carbonate…
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27 sep develop a model does a rumor spread faster in a gym where all of…
A rumor spreads faster in a gym with freely moving students. Analogy: Freely moving students = delocalized electrons in metals (good conductivity); students confined to desks = fi…
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2 the inorganic substances required by your body are called ___________…
minerals
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sep plan an investigation you want to compare the malleability of two m…
1. **Materials**: Two metals (e.g., copper and aluminum) cut into identical rectangular strips (same size, thickness, mass), a hammer, a flat anvil, a ruler, a balance. 2. **Proce…
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a. calculate \\( \\delta t \\) and show your work. b. is the reaction e…
a. \(\Delta T = - 6.4^{\circ}C\) b. The reaction is endothermic.
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particle motion is what type of energy? chemical energy potential energ…
kinetic energy
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when water freezes, what happens to the volume of the sample? it decrea…
It increases.
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when water freezes, what happens to the volume of the sample? it decrea…
It increases.
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periodic table of the elements most elements (75%) are classified as tr…
- Most elements (75%) are classified as \boxed{metals} (specifically, a large portion are transition metals, but the general classification for the majority is metals). - Transiti…
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16. the least reactive metal is found in a) group 1 b) group 2 c) group…
d) d - block ### Question 17
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chemical bonding 101 in the reading below, use a highlighter to highlig…
1. A stable atom has electrons filling its valence shell. 2. A covalent bond is formed when atoms share electrons to become stable. 3. The atom becomes charged (either positive or…
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13. electron affinity is the tendency to: a) gain an electron b) lose a…
a) Gain an electron ### Question 14
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effigy mounds are often created in what type of shape? human geometric …
1. Animal 2. Stela