Química
Reacciones químicas, estequiometría, estructuras moleculares y propiedades.
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which statement correctly compares synthesis and decomposition reaction…
Synthesis and decomposition reactions are opposites of each other. Synthesis reactions are in the form A + B → AB, while decomposition reactions are in the form AB → A + B.
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grinding a tylenol tablet into powder increases the rate of reaction du…
surface area
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which of these is not a pure substance? h2o lemonade the element gold
lemonade
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why does a higher concentration increase the rate of reaction? (1 point…
It increases the frequency of collisions.
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which of these elements on the periodic table is the most electronegati…
F
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a homogeneous mixture is also called * chemically bonded a compound a s…
1. D. a solution 2. B. heterogeneous 3. C. granite
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exam 2: periodicity & electron configuration/em spectrum which of the f…
Energy is absorbed in order for an electron to move from the ground state to the excited state.
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balance the equations by adding whole number co 1. h₂ + o₂ → h₂o 2. n₂ …
1. $2H_2+O_2 = 2H_2O$ 2. $N_2 + 3H_2=2NH_3$ 3. $C_3H_8+5O_2 = 3CO_2+4H_2O$ 4. $4Fe+3O_2 = 2Fe_2O_3$ 5. $2Al + 6HCl=2AlCl_3+3H_2$ 6. $2KClO_3=2KCl + 3O_2$ 7. $2Na+2H_2O = 2NaOH+H_2$
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exam 2: periodicity & electron configuration/em spectrum the most react…
The most reactive group of metals is group 1 and the most reactive group of nonmetals is group 17.
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what happens to mass during a chemical reaction? * mass is neither dest…
1. mass is neither destroyed or created 2. the smallest unit of stuff 3. homogeneous
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exam 2: periodicity & electron configuration/em spectrum considering th…
D. Chlorine
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which of the following is not a physical change? * 2 points - grating c…
1. C. processing/creating cheese 2. C. rusting 3. B. decays
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6. kclo₃ → kcl + o₂ 7. na + h₂o → naoh + h₂ 2na + 2h₂o → 2naoh + h₂ 8. …
6. $2KClO_3 ightarrow 2KCl + 3O_2$ 7. $2Na+2H_2O ightarrow 2NaOH + H_2$ 8. $CaCO_3 ightarrow CaO+CO_2$ 9. $Pb(NO_3)_2 + 2KI ightarrow PbI_2+2KNO_3$
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what is a physical change that you can do to a piece of paper? * 2 poin…
1. C. make a paper airplane 2. D. ability to react with oxygen 3. A. there must be a change in chemical properties to make a new substance
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exam 2: periodicity & electron configuration/em spectrum all of the fol…
Atomic Radius
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classification of matter worksheet homogeneous vs. heterogeneous matter…
Homogeneous vs. Heterogeneous: 1. Heterogeneous 2. Heterogeneous 3. Heterogeneous 4. Homogeneous 5. Heterogeneous 6. Homogeneous 7. Homogeneous 8. Homogeneous 9. Heterogeneous 10.…
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oil floats on top of water. this means that oil is ____ dense than wate…
1. B. less 2. B. compound 3. A. 10 g
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exam 2: periodicity & electron configuration/em spectrum the periods an…
D. krypton (Kr), group 18
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exam 2: periodicity & electron configuration/em spectrum what is the or…
1s: ↑↓ 2s: ↑↓ 2p: ↑↓ ↑↓ ↑↓ 3s: ↑↓ 3p: ↑↓ ↑ ↑
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exam 2: periodicity & electron configuration/em spectrum a measure of t…
C. electronegativity
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exam 2: periodicity & electron configuration/em spectrum the element wi…
B. V
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exam 2: periodicity & electron configuration/em spectrum a family of el…
A. Group 17
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26. carbon, the most essential element for life has an atomic number of…
the number of protons
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exam 2: periodicity & electron configuration/em spectrum which sequence…
I, Br, Cl, F
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to find out the standard, custom, and pantone color codes applied to a …
Click Font on the Home ribbon, from the drop - down menu click the "More Colors" option.
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exam 2: periodicity & electron configuration/em spectrum which elements…
D. b and c are both correct answers.
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exam 2: periodicity & electron configuration/em spectrum many propertie…
[Ar] 4s²3d²
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minerals are inorganic substances that the body cannot produce on its o…
T
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learning target i can identify patterns on the periodic table and use t…
Calcium (Ca) is more electronegative. This is because it is located in group 2 and has an atomic number of 20. Having a higher atomic number means that it has more protons in the …
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learning target i can identify patterns on the periodic table and use t…
4a. Calcium; 2; 20; higher; more; stronger 4b. As we go down group II, the reactivity of metals with carbonate, sulfate and iodate generally increases. Magnesium shows no reaction…
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3b. which element would be more reactive, chlorine or argon? justify yo…
Chlorine has 7 valence electrons while argon has 8. Both chlorine and argon complete their octets by having 8 valence electrons. Since chlorine has to gain 1 electron to complete …
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learning target i can explain the properties of the main groups on the …
Group: Organizes elements with similar properties together where each element has the same number of valence electrons. Noble Gases: All elements in this group have full outer ene…
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2d. complete the following table by identifying how many valence electr…
| Element Name | Valence Electrons | Gains or Loses Electrons? | How many? | Resulting Charge | | --- | --- | --- | --- | --- | | Magnesium (Mg) | 2 | Loses | 2 | +2 | | Gallium (…
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3. describe any relationships within a group between atomic number and …
3. Generally, as atomic number increases in a group, boiling - point can increase due to stronger intermolecular forces. 4. Yes, elements in the same group have similar physical c…
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3. describe any relationships within a group between atomic number and …
3. Elements in the same group have similar outer - electron configurations which leads to similar physical properties related to boiling and melting points. As atomic number incre…
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what can cause weathering? (check all that apply) chemical water wind p…
All of the above (Chemical, Water, Wind, Plants, Animals)
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2c. identify the number of valence electrons for the following element …
4
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24. in the graph to the right, an increase in temperature results in * …
B. An increase in reaction rate.
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2. how many protons and neutrons are present is an atom of krypton (mas…
2. Protons = 36, Neutrons = 48 3. Protons = 50, Neutrons = 69 4. Protons = 74, Neutrons = 110 5. Protons = 22, Neutrons = 26
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29. which part of an atom is represented by the yellow circles in the o…
electron
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2b. below is a bohr model of a neutral atom. based on the model, a stud…
The student is incorrect. The atom has 1 valence electron.
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2. water is often called the \universal solvent\ because many substance…
b. Polarity and cohesion
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part b while studying chemical and physical changes, students added sal…
B. No, it is a physical change. It is salt and water and you can get the salt back by boiling off the water.
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part a consider the images depicting change. which statement accurately…
D. The pipes in image I are going through a chemical change called rusting, the evidence is the color change.
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following is a list of observations from a chemistry laboratory. place …
Evidence of a chemical change: Burning toast, A candle being lit, A white cloudy substance occurs after mixing two clear solutions, A car rusting, Leaves changing color in October…
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day 24 name aaron comestrae date 9/30/25 period 3 score ws phase diagra…
1. Liquid CO₂ will freeze into solid CO₂. 2. Liquid CO₂ will vaporize/boil into gaseous CO₂. 3. Liquid CO₂ will vaporize/boil into gaseous CO₂. 4. Liquid CO₂ will become a compres…
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1d. complete the table below. (2 points) element name mass number proto…
| Element Name | Mass Number | Protons | Neutrons | Electrons (neutral atom) | | ---- | ---- | ---- | ---- | ---- | | Barium | 138 | 56 | 82 | 56 | | Sulfur | 50 | 16 | 34 | 16 |
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which of the following do water (h₂o), rust (fe₂o₃), and salt (nacl) ha…
A. water, rust, and salt are elements - Incorrect B. water, rust, and salt are heterogeneous mixtures - Incorrect C. water, rust, and salt are homogeneous mixtures - Incorrect D. …
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1b. what element is shown in the diagram above (1a)? explain how you kn…
Nitrogen. The element is identified by the number of protons in the nucleus, and since there are 7 protons, it is nitrogen.
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the circles and dots in the boxes below represent atoms of two differen…
B. Box M
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identify each of the images as an element, molecule or compound.
A. element B. molecule C. compound
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pure substance or mixture part a matter can be classified as either a p…
PART A: D. III PART B: A. I
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to rent a certain meeting room, a college charges a reservation fee of …
$0\leqslant t\leqslant8.5$
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from: rena nelson to: vella cruz subject: alicia cruz ms. cruz, i am ha…
I would
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what number and types of atoms occur in a formula unit of ca(no₃)₂? 1 c…
1 calcium atom, 2 nitrogen atoms, and 6 oxygen atoms
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to rent a certain meeting room, a college charges a reservation fee of …
$t\geq0$
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part 4: local geology connection 1. what type of rocks are the granite …
1. Igneous rocks. 2. It has diverse geological formations, rock - types, and active geological processes. 3. The vinegar - related process in the lab. 4. The sandpaper - related p…
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how are ionic compounds formed? electrons are transferred between a met…
Electrons are transferred between a metal and a nonmetal.
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which of the following is the correct electron configuration of the chl…
1s²2s²2p⁶3s²3p⁶
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dtal - ch - term 1 - unit 4a assessment - 25 - 26 due: wed oct 1, 2025 …
C. Ne, D. Na⁺
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available: oct 1, 2025 8:30am until oct 1, 2025 10:30am details no addi…
D. $MnCl_{3}$
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available: oct 1, 2025 8:30am until oct 1, 2025 10:30am details no addi…
$Ca_3P_2$
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in a certain meeting - room, a college charges a reservation fee of $13…
$t\leq12$
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available: oct 1, 2025 8:30am until oct 1, 2025 10:30am details no addi…
Mg²⁺, Br⁻; MgBr₂
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learning target i can describe the charge, location, and masses of suba…
From top - left clockwise: 1. Energy levels/shells 2. Electron 3. Proton 4. Neutron 5. Nucleus 6. Electron 7. Energy levels/shells
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hester, treyvon dial - ch - term 1 - unit 4a assessment - 25 - 26 what …
$SnO_{2}$
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hester, treyvon dtal- ch- term 1 - unit 4a assessment- 25-26 a solid su…
CuBr₂
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data table 1. mass of evaporating dish 50.17 g 2. mass of hydrate 2.49 …
$39.0$
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1. mass of evaporating dish 56.17 g 2. mass of hydrate 2.49 g 3. mass o…
1. Approximately $37.75\%$ 2. No 3. (already given in the problem: $MgSO_4\cdot7H_2O$: $51.2\%$, $Ca(NO_3)_2\cdot4H_2O$: $30.5\%$) 4. $3.195$ g
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data table 1. mass of evaporating dish 56.17 g 2. mass of hydrate 2.49 …
1. $36.1\%$ 2. No 3. $MgSO_4\cdot7H_2O$: $51.2\%$, $Ca(NO_3)_2\cdot4H_2O$: $30.5\%$ 4. $3.195\ g$
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11. today, carbon dioxide is a part of the oxygen - cycle that keeps al…
It helped keep the planet warm and was involved in key chemical processes for life - relevant substances formation.
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u2 pretest 1. which accounts for most of the mass of an atom? a. electr…
1. c. neutrons and protons 2. d. 5 protons, 6 neutrons 3. a. Periods 4. d. a nonmetal 5. b. Al and Ga 6. b. phosphorus (P)
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analysis and conclusions 1. for each case in which you found a reaction…
| |$K_3PO_4$|$KOH$|$K_4Fe(CN)_6$|$K_2CO_3$|$KI$|$K_2C_2O_4$| |---|---|---|---|---|---|---| |$Co(NO_3)_2$|$Co_3(PO_4)_2$|$Co(OH)_2$|$Co_3[Fe(CN)_6]_2$|$CoCO_3$|NR|$CoC_2O_4$| |$Pb(…
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instrucciones: lee y anota las reglas de la clase. marca c si es cierto…
1. F 2. F 3. F 4. C 5. C 6. F 7. F 8. F 9. F 10. C
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a thermometer is placed in water in order to measure the waters tempera…
The kinetic energy of the water molecules decreases.
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4. which process do scientists believe brought water to the earth stars…
Water present in meteorites, comets and asteroids colliding with the earth.
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short answer / writing prompt does combining two or more substances alw…
No, combining two or more substances does not always result in a chemical reaction because in mixtures, substances are physically combined and retain their original properties wit…
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a thermometer is placed in water in order to measure the waters tempera…
The molecules in the thermometer's liquid spread apart.
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3. what is the main difference between a solution and a colloid? a) sol…
3. B. Solutions have particles smaller than 1 nanometer; colloids have particles between 1 and 1000 nanometers 4. C. Particles are large enough to settle over time and can be sepa…
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multiple choice questions 1. what defines a mixture in chemistry? a) tw…
1. B. Two or more materials combined without breaking or forming chemical bonds 2. C. Lava lamp (water and wax) 3. (Incomplete question, but if based on the known part of the diff…
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hester, treyvon dtal - ch - term 1 - unit 4a assessment - 25 - 26 all o…
A. ionic compounds exhibit low melting points
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hester, treyvon dtal - ch - term 1 - unit 4a assessment - 25 - 26 which…
B. MgO
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hester, treyvon dtal - ch - term 1 - unit 4a assessment - 25 - 26 choos…
lead II nitrate
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hester, treyvon dtal - ch - term 1 - unit 4a assessment - 25 - 26 choos…
lithium sulfate
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choose the correct name for: fe2o3 iron oxide iron ii oxide iron iii ox…
iron III oxide
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hester, treyvon dtal - ch - term 1 - unit 4a assessment - 25 - 26 choos…
copper I sulfide
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exit ticket: write the full electron - configuration and draw the orbit…
1. Boron electron configuration: $1s^{2}2s^{2}2p^{1}$ 2. Helium electron configuration: $1s^{2}$ 3. Sulfur electron configuration: $1s^{2}2s^{2}2p^{6}3s^{2}3p^{4}$ 4. Argon electr…
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who first proposed that matter was composed of atoms? o boyle o thomson…
C. Democritus
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noble gases are not very reactive due to their full valence shells. tru…
True
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halogens generally tend to: lose two or three electrons lose one electr…
gain one electron
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18. what is the role of neurotransmitters in neuron communication? give…
The role of neurotransmitters in neuron communication is to act as chemical messengers to transmit signals across synapses. An example of a neurotransmitter is dopamine.
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what is the chemical formula for carbon dioxide?
CO₂
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¿un ejemplo de fase as un ejemplo físico y químico? lea el siguiente te…
# Explicación: ## Paso 1: Definir cambio físico Un cambio físico es aquél en el que la sustancia mantiene su identidad química, solo cambia su estado físico (sólido, líquido, gase…
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3. how are elements and compounds similar? how are they different? 4. w…
3. Elements and compounds are both pure substances. Elements have one - type of atom, compounds have different types of atoms chemically combined. 4. Mixtures are physically combi…
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chemistry unit 1b practice ws#3 section 3.3 mixtures of matter t/f (if …
1. - 1. T - 2. F (Pure substances have fixed composition.) - 3. F (Elements cannot be chemically broken down into simpler substances.) - 4. F (Compounds can only be separated into…
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on place un bloc de glace sèche (du dioxyde de carbone solide) de 5.6 g…
The pressure in the empty container is approximately $79.3\ kPa$. The partial pressure of CO₂ in the container with air is $79.3\ kPa$, and the total pressure is $178.3\ kPa$.
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which respirator would be used where dust or solid particles might be i…
D. half mask or mouthpiece with a mechanical filter
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select the correct answer. who was the first to state the concept of an…
A. Democritus
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select the correct answer. what defines the mass number of an isotope? …
A. the sum of the neutrons and protons
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multiple choice question the term isotope describes two or more atoms w…
two or more atoms with the same atomic number but different mass numbers