化學
化學反應、化學計量、分子結構與元素性質。
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types of reactions 12 multiple-choice question in a double displacement…
nonmetals
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3. click the attribute, \atomic radius\ to color - code the elements fo…
- The atomic radius increases as you move down a group. - The atomic radii from largest to smallest are barium (Ba), calcium (Ca), bromine (Br), and fluorine (F). - The atomic rad…
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some bad news. youve been caught by a secret fbi agent before you could…
| Identify the 5 most common scams | Groups involved in this Scam | What are the general “red flags” about this scam that citizens should watch out for? (these are aspects of the …
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the bohr models of the first 20 elements are shown in the diagram. whic…
The first, second, fourth, and fifth statements are correct.
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types of reactions classifying reactions-types of chemical reactions ab…
Two bonded compound switch ions.
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4. which is a physical property of matter? a corrosion b flammability c…
D. volume
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carbon (c) and oxygen (o) are in the same period on the periodic table …
Carbon (C) and oxygen (O) are in the same period on the periodic table and have different atomic numbers.
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13 multiple - choice question which type of atoms did the silver re - c…
bromine
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select the correct statement(s). hydrogen (h) and lithium (li) are in t…
Hydrogen (\(H\)) and lithium (\(Li\)) are in different periods on the periodic table and have different numbers of electron shells or energy levels. ; Hydrogen (\(H\)) and lithium…
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use the formula for density, d = m/v, where d is density, m is mass, an…
C. silver
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types of reactions jack cadman chemistry lesson types of chemical react…
hydrogen
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to build an electrically neutral model of a with an atomic mass of 7. s…
- Lithium (\(Li\)) is found in the same group as hydrogen (\(H\)) and has one valence electron. - Lithium (\(Li\)) has three protons and an atomic number of 3. - Lithium (\(Li\)) …
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types of reactions chemistry lesson types of chemical reactions ah→a+b …
\(2H_2O(l) ightarrow2H_2(g)+O_2(g)\) and \(NH_4Cl(s) ightarrow NH_3(g)+HCl(g)\) and \(2KCl ightarrow2K + Cl_2\) are decomposition reactions.
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what are the properties of alkali metals. check all that apply(6) all t…
Atoms have a single electron in their outermost level, in other words, 1 valence electron; found in the first column of the periodic table.
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read the following excerpt from upton sinclairs the jungle. \there was …
Expose corruption or social injustice to provoke public outrage and demand reform
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scenario a student hypothesizes that melting ice decreases the total ma…
C. La hipótesis es valiosa porque demostró que los cambios físicos conservan la masa y puede conducir a nuevas investigaciones.
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select the correct statement(s) about an electrically neutral atom of a…
- It has 3 electron shells (energy levels). - It has 18 total electrons. - It has 8 valence electrons. - It has 18 protons and an atomic number of 18.
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during science class, while studying mixtures, you mix together iron fi…
D. Use a magnet to pull out the iron filings as they are attracted to a magnet.
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they prepare two samples: • sample a: pure water • sample b: water with…
# Explicación breve: En un experimento, para que los resultados sean válidos, se deben controlar las variables que no son la variable independiente (en este caso, la presencia o a…
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carbon dioxide has a density of 0.002 g/ml. soda has a density closer t…
# Explicación breve: La densidad del dióxido de carbono (\(0,002\ g/ml\)) es menor que la densidad del agua (aproximadamente \(1\ g/ml\)). Cuando el dióxido de carbono se desprend…
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which best explains how the law of conservation of mass is present in a…
A. The number of atoms of each element making up reactants equals the number of atoms of the same elements making up the products.
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question 2 of 4 hydrogen atoms are removed during and oxidation reactio…
True
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a liquid with a mass of 56g and a tablet with a mass of 14g are placed …
A. Two grams were lost as a gas during the reaction since this occurred in an open beaker.
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which best explains how a mixture and a compound compare? a. a mixture …
A. A mixture can be physically separated and a compound can be chemically separated.
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how would the placement of nonmetals on the periodic table of elements …
B. They are located in the upper right corner.
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select the correct statement(s). atomic number increases from left to r…
Atomic number increases from left to right across a period, Atomic mass increases as you move down a group, The number of protons and the number of electrons are equal in a neutra…
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which result is due to a chemical reaction? a. water forms a gas. b. dr…
C. Gas forms after mixing vinegar and baking soda.
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select the correct statement(s). elements are organized into horizontal…
- Elements are organized into horizontal rows on the periodic table. They are called periods. - All matter is made up of one or more atoms. - Elements are organized into vertical …
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16 mark for review of the x atoms in a certain molecule, 45% are carbon…
B. \(0.45x\)
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which most likely has occurred when two or more liquid substances that …
D. production of a new substance with new properties
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how are the atomic mass numbers of the elements arranged on the periodi…
D. Atomic mass increases from left to right.
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when two clear liquids are combined, a pink powder forms and sinks to t…
D. chemical reaction, because a precipitate formed in the test tube
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how can the periodic table of elements be used to find the number of el…
D. The atomic number tells how many electrons are in an element.
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how can the periodic table of elements be used to find the amount of su…
A. The atomic number gives the number of protons and electrons and the atomic mass minus the atomic number gives the number of neutrons.
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many periodic tables have a heavy, dark, staircase - shaped line on the…
B. Metals are located to the left of the staircase line, and nonmetals are located to the right of the staircase line.
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why are subscripts used in chemical formulas? a. to decrease the amount…
C. to show how many of each kind of atom is in a compound
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how many electrons does a neutral atom of li have? 1 2 3 4
3
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how many electrons does li+ have? * 1 2 3 4
2
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how many electrons does li - have? * 1 2 3 4
4
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what is the atomic mass (amu) of silver? * 47 ag silver 107.868 ag 47 1…
107.868
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what does the atomic mass unit represent? * the mass of one proton or n…
The mass of one proton or neutron, approximately.
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question 6 (1 point) saved calcium hydroxide and phosphoric acid react …
neutralization
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2 (nh₄)₃po₄ ammonium phosphate how many total atoms are in 2 (nh₄)₃po₄?…
\(40\)
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how many hydrogen atoms are in 2 (nh4)3po4?
\(24\)
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4 cacl₂ calcium chloride how many total atoms are in 4 cacl₂? 4 atoms 3…
12 Atoms
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how many oxygen (o) atoms are in 4 co₂? 2 oxygen atoms 8 oxygen atoms 6…
8 Oxygen Atoms
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question 6 of 10 4 co₂ carbon dioxide how many molecules are in 4 co₂? …
4
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which of the following correctly counts the atoms in ca₃(po₄)₂? 3 ca, 2…
3 Ca, 2 P, 8 O
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how many total atoms are in al₂(so₄)₃? 17 3 12 24
\(17\)
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how many oxygen atoms are in al(so₄)? 3 17 12 4
12
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question 23 what is the formula for carbonic acid? question 24 write th…
Question 23: \(H_{2}CO_{3}\) Question 24: Disulfur decafluoride
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question 12 1,000 pts lonic bonds form because... two atoms share their…
two ions of different charges are electrically attracted to each other. # Question 13
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question 10 1,000 pts covalent bonds form because... o two atoms share …
two atoms share their electrons. # Question 11
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acid formulas start with h true false question 4 10,000 pts covalent co…
- Question 4: True - Question 5: False
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carbon and chlorine form a covalent compound whose formula is ccl₄. the…
First question: Carbon Tetrachloride Second question: nitrogen dioxide, \(NO_2\)
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the name for the compound s₂o₄ is ____________. sulfide trioxide disulf…
First question: B. disulfur tetraoxide Second question: D. \(N_2O\)
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a lab technician knows that the empirical formula of a molecule is ch₂.…
D. \(C_4H_8\)
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one method for determining the identity of an unknown organic compound …
B. \(CH_{2}\)
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periodic table calcium fluoride (caf₂) is a major component in human te…
D. \(51.3\%\space Ca, 48.7\%\space F\)
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when a 16.50 - g sample containing nickel and oxygen is analyzed, 5.87 …
\(35.6\%\) nickel, \(64.4\%\) oxygen
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states that every sample of the same substance contains identical eleme…
The law of definite proportions
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combination (synthesis) a + b → ab zn(s) + cl₂(g) → zncl₂(s) what type …
Synthesis
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what are the products of a combustion reaction? rewatch skip oxygen wat…
carbon dioxide, water
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types of chemical reactions type of reaction combination (synthesis) de…
Hydrocarbon, Oxygen
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classify each of the following as a combination, decomposition, single …
Single displacement reaction.
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classify each of the following as a combination, decomposition, single …
Combustion reaction.
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write the formula for copper(ii) sulfate. * your answer name the compou…
1. \(CuSO_{4}\) 2. Potassium manganate 3. \(2Al + Fe_{2}O_{3}\to 2Fe+Al_{2}O_{3}\) 4. \(2C_{4}H_{10}+13O_{2}\to 8CO_{2}+10H_{2}O\) 5. \(2Na_{3}PO_{4}+3CaCl_{2}\to Ca_{3}(PO_{4})_{…
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classify each of the following as a combination, decomposition, single …
Decomposition reaction.
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cooling curve a cooling curve shows how the temperature (y - axis) chan…
- Kinetic energy is (lost) during a cooling curve therefore the temperature goes (down). - The substance starts in the (gas) phase. - At the first plateau where temperature is (co…
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1 multiple choice 2 points which of the following is an example of a se…
1. Ground - level ozone 2. Burning fossil fuels 3. Pollutants formed in the air from chemical reactions
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write the formula for iron (iii) carbonate. * your answer this is a req…
- Iron (III) carbonate: \(Fe_{2}(CO_{3})_{3}\) - \(Pb(NO_{3})_{2}\): Lead (II) nitrate - \((NH_{4})_{2}Cr_{2}O_{7}\): Ammonium dichromate - Sulfurous acid: \(H_{2}SO_{3}\) - \(Ni(…
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classify the reaction: 2c₂h₂ + 5o₂ → 4co₂ + 2h₂o your answer classify t…
1. Combustion reaction 2. Synthesis (combination) reaction 3. Decomposition reaction
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5. as the mass of the nucleus increases, what happens to the ratio of n…
The neutron:proton ratio increases.
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law of conservation of mass worksheet 1. define the law of conservation…
A) \(13.4g\) B) \(6.2g\) C) \(10.6g\) D) \(9.45g\) E) \(28.8g\) F) \(126g\) G) \(14.3g\)
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3. which of the following is the correct notation for an isotope with 3…
\(_{3}^{8}\text{Li}\) (assuming the option with \(_{3}^{8}\text{Li}\) is present. If we consider the given options, likely there was a mis - label (maybe a typo in the problem's o…
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balance the following equation: na₂co₃ + hcl → nacl + h₂o + co₂ your an…
1. \(Na_{2}CO_{3}+2HCl = 2NaCl + H_{2}O+CO_{2}\) 2. Decomposition reaction 3. Single - replacement reaction 4. Acid - base reaction (or reaction between a base and an acidic oxide)
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2. how many protons and neutrons does iron - 56 have? 56 26 fe 26 proto…
26 protons and 30 neutrons
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balance the following equation:* nh₃ + o₂ → no + h₂o your answer this i…
\(4NH_3+5O_2 = 4NO + 6H_2O\)
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paper chromatography is used to ________. produce glucose force photosy…
For the first question: separate components in a material of interest. For the second question: algae.
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balance the following equation: kmno₄ + hcl → kcl + mncl₂ + cl₂ + h₂o y…
1. \(2KMnO_{4}+16HCl = 2KCl + 2MnCl_{2}+5Cl_{2}+8H_{2}O\) 2. \(4NH_{3}+5O_{2}=4NO + 6H_{2}O\) 3. \(2C_{3}H_{8}O+9O_{2}=6CO_{2}+8H_{2}O\) 4. \(4FeS_{2}+11O_{2}=2Fe_{2}O_{3}+8SO_{2}…
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question what is the formula of barium phosphate? a. ba₂(po₄)₂ b. ba₃(p…
C. \(Ba_{3}(PO_{4})_{2}\)
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question 14. a student writes the name for mgf₂ as magnesium (ii) fluor…
D. Mg is not a transition element; thus, it does not need to have a roman numeral on its name.
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question 13. the formula unit for the compound tin (iv) dichromate is _…
B. \( Sn(Cr_2O_7)_2 \)
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air contains oxygen, nitrogen, hydrogen and water vapor. none of these …
homogeneous mixture
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question 12. what is the formula unit for the compound iron (iii) nitri…
A. FeN
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how many different atoms are represented in the model shown: 1 2 3 4
2
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question what is the name of the compound k₂o? a. potassium oxide b. po…
A. Potassium oxide
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parea cada tipo de onda electromagnetica con su descripcion radio waves…
Radio waves - Very low energy wave. Wi - Fi is an example. Microwaves - EM wave which causes water molecules in food to vibrate. Visible Light - The only electromagnetic waves we …
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how many electrons in the ion pb3+ with 82 protons. 79 85 82 161 an ato…
For the first question: 79. For the second question: An ion of beryllium.
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parea cada t romagnetica con su descripcion. radio waves/ondas de radio…
Radio waves: Very low energy wave. WiFi is an example. Microwaves: EM wave which causes water molecules in food to vibrate. Visible Light: The only electromagnetic waves we can ob…
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1) where do you need to orient your eye level to take an accurate readi…
A. Exactly parallel to the meniscus
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question what is the formula of barium phosphate? a. $\\ce{ba_{2}(po_{4…
C. \(Ba_{3}(PO_{4})_{2}\)
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which compound is a carbohydrate? (1 point) na2c2o4 c4h12n2 hclo4 c3h6o3
\(C_3H_6O_3\)
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why are isotopes with a neutron:proton ratio far from the band of stabi…
They have an unstable nucleus.
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mg+2 has the same number of electrons as: mg ne si which of the followi…
First Question: Ne Second Question: they have different numbers of neutrons
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chemical reaction predictions quick check what can be predicted from th…
band type between the atoms
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an element has an atomic number of 45 and an atomic mass of 98. how man…
1. \(53\) 2. \(41\) 3. The neutral atom of the element gained 3 electrons.
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what element is shown in the model: (protons = red, neutrons = yellow, …
- First question: boron - Second question: protons, neutrons
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chemical reaction predictions quick check which term describes the conv…
chemical reaction
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select the statement that is true for the model of the atom shown. * th…
This atom is neutral because the protons and electrons are equal