Química
Reacciones químicas, estequiometría, estructuras moleculares y propiedades.
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what charge does al typically have in ionic compounds, and why? a +1, b…
C. +3, because it has three valence electrons.
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based on the positions of elements in the periodic table, which of the …
A. \(KCl\), \(KBr\), and \(KI\)
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which is equal to the mass number of an atom? number of protons protons…
protons plus neutrons
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if na reacts with chlorine to form nacl, which of the following element…
D. Br, because it has the same number of valence electrons as Cl.
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multiple choice question for atoms to be different isotopes of an eleme…
neutrons
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fill in the blank question the number of in an atoms nucleus is equal t…
protons
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question 1 (1 point) why does the boiling point of an alkane increase a…
d) The strength of the dispersion forces increases with increased molecular size.
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select all that apply which statements about how scientists use models …
- Models of atoms are examples of scaled - up models. - Models help scientists visualize atoms because atoms are too small to see. - Models show the distances between subatomic pa…
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for element x represented above, which of the following is the most lik…
C. The electron removed during the third ionization is, on average, much closer to the nucleus than the first two electrons removed were.
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the complete photoelectron spectrum of an element is given above. which…
B. Peak X, because 1s electrons have the strongest attractions to the nucleus.
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the photoelectron spectra for h and he are represented above. which of …
B. He has a greater nuclear charge than H and an additional electron in the same energy level.
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fill in the blank question the of an atom is the sum of the number of p…
mass number
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atoms of mg combine with atoms of f to form a compound. atoms of which …
B. Ba
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fill in the blank question the mass of an atom is measured in need help…
atomic mass units (amu or u)
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has the highest electronegativity a cs b pb c br d se
C. Br
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has the largest atomic radius a cs b pb c br d se
A. Cs
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below are two atomic models. each model represents a different atom. co…
electrons
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has the lowest first - ionization energy a cs b pb c br d se
A. Cs
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protons and neutrons are found in the nucleus of an atom. traveling aro…
An electron has a negative electrical charge. All of an atom's electrons are located outside its nucleus.
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which of the following ions has the same number of electrons as br-? a …
B. \(Sr^{2+}\)
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what charge does al typically have in ionic compounds, and why? a +1, b…
C. +3, because it has three valence electrons.
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in a certain chemical, the ratio of zinc to copper is 4 to 11. a jar of…
\(180\)
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based on the positions of elements in the periodic table, which of the …
A. \(KCl\), \(KBr\), and \(KI\)
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if na reacts with chlorine to form nacl, which of the following element…
A. K, because it is in the same group as Na.
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for element x represented above, which of the following is the most lik…
C. The electron removed during the third ionization is, on average, much closer to the nucleus than the first two electrons removed were.
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the complete photoelectron spectrum of an element is given above. which…
B. Peak X, because 1s electrons have the strongest attractions to the nucleus.
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what is \\( \\delta h^{\\circ}_{rxn} \\) for the following reaction? \\…
$82.1$ kJ/mol
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using hesss law, what is δh° rxn for the following reaction? wo₃(s) + 3…
\(117.5\space kJ/mol\)
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15. explain how potassium and phosphorus make an ionic compound.
Potassium (a metal) donates electrons to become \(K^{+}\) ions, phosphorus (a non - metal) accepts electrons to become \(P^{3 -}\) ions. These oppositely charged ions are held tog…
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the photoelectron spectra for h and he are represented above. which of …
B. He has a greater nuclear charge than H and an additional electron in the same energy level.
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what is \\( \\delta h_{\\mathrm{rxn}}^{\\circ} \\) for the following re…
-226.5 kJ
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when 0.550 g of na(s) reacts with excess f2(g) to form naf(s), 13.8 kj …
\(\text{O}-567\space kJ/mol\)
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if 75.4 j of energy is absorbed by 0.25 mol of ccl4 at constant pressur…
C. \(2.3^{\circ}C\)
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what is q if 28.6 g of water is heated from 22.0°c to 78.3°c? the speci…
\(6.74kJ\)
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the specific heat (capacity) is o the amount of energy needed to increa…
the amount of energy needed to increase the temperature of 1 g of a substance by 1°C.
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fill in the blank complete each statement using a term or terms from th…
**Fill - in - the - blank** 1. rain water, carbonic acid 2. new products 3. oxide 4. rust 5. crumbles 6. the air 7. carbon dioxide 8. the air 9. underground caves 10. speeds **Mat…
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mechanical or chemical weathering study each diagram below which shows …
1. mechanical 2. is not 3. mechanical 4. is not 5. mechanical 6. is not 7. mechanical 8. is not
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mechanical or chemical weathering study each diagram below which shows …
1. mechanical 2. is not 3. mechanical 4. is not 5. mechanical 6. is not 7. mechanical 8. is not
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8. find the mass of a 50.0 ml quantity of water if the density of water…
$50.0\ g$
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7. a pencil has a density of.875 g/ml. it has a mass of 3.5 grams. what…
The volume of the pencil is $4$ ml.
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b. the iron comes from the rock. where does the oxygen come from? (the …
1. the air 2. iron oxide 3. warm and moist 4. chemical 5. carbonic acid 6. carbon dioxide; water 7. the air 8. chemical 9. does 10. does
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the basics of argument--practice quiz 4 (80% or higher) look at the thr…
B. Great damage has been caused by bringing foreign plants and animals to new lands.
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10 what is the rule for finding out how many valence electrons elements…
10. The number of valence electrons = group number - 10. 11. Atoms gain or lose electrons to form ions. 12. Positive ion. 13. Negative ion. 14. Because the number of protons and e…
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chemical bonding review worksheet 1. which part of the atom is responsi…
1. Electrons 2. The electrons in the outermost shell of an atom involved in bonding 3. In the outermost electron shell (valence shell) 4. 8 5. Hydrogen and Helium 6. Hydrogen has …
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question 8 of 10 read this appeal: not only is meat more expensive than…
C. The local school board
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why is the vapor pressure of water important in this experiment? select…
The trapped gas inside of the graduated cylinder is a mixture of water and butane.
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4 fill in the blanks with the word physical to describe a physical chan…
1. physical 2. chemical 3. chemical 4. physical 5. chemical
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3 which of the following statements is true about the physical properti…
A. They can be observed without changing the substance chemically.
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2 the stomach in the human body contains acid that breaks down food int…
D. An example of a chemical change
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1 which of the following examples is not a physical change? a a person …
C. Rust forming on a bicycle chain
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13. the first chemical digestion in the human digestive system takes pl…
B. oral cavity
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2. practice: in the gizmo, create atoms that have a specific number of …
| Protons | Neutrons | Electrons | Element Name | Element Symbol | | ---- | ---- | ---- | ---- | ---- | | 3 | 4 | 3 | Lithium | Li | | 4 | 5 | 4 | Beryllium | Be | | 7 | 7 | 7 | N…
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for the electronic configuration given, choose the electronic configura…
\(1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^{6}5s^{2}\)
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q1. choose the correct answer for each of the following: a) the mass in…
a) The mass percent of oxygen in \(CaO\) is approximately \(28.5\%\) b) The amount of moles of methane is approximately \(0.94\space mol\)
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available after 22 oct 2025 13:00 details no additional details were ad…
the pattern of rhymes at the end of each line of a poem
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available after 22 oct 2025 13:00 details no additional details were ad…
a group of lines forming a unit within a poem
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21.7 ml of gas at 98.8 kpa is allowed to expand at constant temperature…
\(40.7\)
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according to gas law, which of the following is/are correct? a temperat…
C. If the number of gas molecules and the temperature remain constant, then the pressure is inversely proportional to the volume
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a 15.0 l tank of gas is contained at a high pressure of 8.20 × 10⁴ torr…
20.5
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a balloon tied to the ground with a rope floats in the air. the volume …
\(0.2\)
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in any chemical reaction, the mass of the reactants equals the mass of …
It describes a repeatedly observed relationship, but it does not offer an explanation.
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a sample of gas y occupies 500 l at the pressure of 80 kpa. after chang…
\(100\)
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a sample of gas x occupies 10 m³ at a pressure of 120 kpa. if the volum…
400
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1pt where is the actinide series located? a. far left of the table b. f…
D. underneath the table
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1pt which of the following is true about transition metals? a. mostly g…
B. mostly solids, luster, high density, conductors
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1pt rows of the periodic table are called? a. periods b. groups c. fami…
A. periods
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1pt how many groups are there in the periodic table? a. 9 b. 27 c. 4 d.…
D. 18
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1pt metalloids are generally_________. ○ a. all solids, shiny, brittle,…
A. all solids, shiny, brittle, conductors, medium density
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1pt the noble gases include which of the following sets of elements? ○ …
A. Ar, Kr
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1pt what are halogens often used for? a. electrical conductors b. therm…
D. light bulbs
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1pt which of the following are properties of alkali metals? a. mostly s…
D. solids, luster, malleable, conductors, reactive
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1pt what are alkaline earth metals used for? a. solar cells b. jewelry …
C. fireworks
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1pt which of the following is true about metals? a. mostly solids, lust…
A. mostly solids, luster, high density, conductors
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1pt where is the lanthanide series located? a. far left of the table b.…
D. underneath the table
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1pt which of the following elements has the most ionization energy? a. …
A. C
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1pt which of the following groups of elements is ranked from most react…
B. S, Se, Te, Po
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1pt which of the following ions has the smallest ionic radius? a. c⁴+ b…
A. \(C^{4+}\)
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electronegativity tends to decrease as you move _________. a. up a colu…
B. down a column on the periodic table
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which of these elements has the most unreactive valence electron config…
A. Ne
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which of the following does not vary according to rows and periods in t…
D. radioactivity
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1pt the reactivity of metals tends to increase as you move a. up a colu…
B. down a column on the periodic table.
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bradley was working in the lab. he accidentally poured a container of c…
C. The solution has now become a good conductor of electricity
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which of the following elements is most likely to react vigorously with…
B. Na
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1pt atomic radius tends to decrease as you move _________. ○ a. up a co…
A. up a column on the periodic table
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1pt metallic character tends to increase as you move in which direction…
B. down a column on the periodic table
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before using any chemical in the lab, why should one first read the mat…
The MSDS provides information on safe handling of the chemical.
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which of these elements is found in both carbohydrates and water? carbo…
B. oxygen
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which term describes a pure substance that is made up of only one type …
element
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what is the basic unit of matter? atom molecule gas compound
atom
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question 19 which of the following describes a scenario involving pesti…
Pesticides found only in Florida in a mountain valley are carried by air currents into the surrounding hills, killing amphibians living in the hills' streams. # Question 20
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which substance is a compound? water gold oxygen hydrogen
water
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check all the characteristics below that describe compounds. two or mor…
- two or more elements - chemically combined elements - definite proportions
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check all the characteristics below that describe elements. one type of…
one type of atom, a pure substance
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question 9 ____ are substances that cause birth defects. teratogens vec…
- **Question 9**: Teratogens - **Question 10**: Pathway inhibitors - **Question 11**: an estrogen mimic used in plastic manufacturing
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22. at 350.0 k, the rate constant for a reaction was found to be 0.0890…
B. \(18.2\space kJ/mol\)
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criss-cross rule lt: i can use the criss - cross rule for ionic compoun…
## Part 1: 1. \(BaBr_{2}\) 2. \(Al_{4}C_{3}\) 3. \(Na_{2}O\) 4. \(CaF_{2}\) 5. \(Li_{3}N\) 6. \(Li_{2}S\) 7. \(SrSe\) 8. \(Sr_{3}N_{2}\) 9. \(K_{2}O\) 10. \(Mg_{3}P_{2}\) ## Part …
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2 which of the following represent the law of conservation of mass?
D.
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question 4 aquatic animals such as fish and frogs are especially good i…
most chemicals are water soluble so they enter these organisms through drinking or skin absorption
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question 2 all of the following statements are true of allergens except…
Everyone is affected by an allergen at a high enough dose.
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question 1 the effect of toxicants on fetuses and young children o has …
is greater because of their developmental immaturity, rapid growth, and smaller biomass