化學
化學反應、化學計量、分子結構與元素性質。
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36. classify classify the following changes as physical or chemical cha…
a. Physical change b. Physical change c. Chemical change d. Chemical change ### 37.
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read the passage, then answer the question that follows. no one could h…
D. It shows that sweeteners did not need to be the product of sugar plantations and slavery
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35. compare what is the main difference betwee physical changes and che…
Physical changes do not change the substance's identity; chemical changes form new substances with different chemical properties.
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28. identify write the chemical symbol for each of the following elemen…
28. a. Pb b. O c. Ag d. Na e. H f. Al 29. a. Carbon b. Calcium c. Potassium d. Gold e. Iron f. Copper 30. Elements: carbon, hydrogen, oxygen, nitrogen. Element with greatest propo…
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26. identify name two methods that can be used to break down compounds …
26. Decomposition, Electrolysis 27. a. Compound b. Mixture c. Mixture d. Element
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which of the following are diatomic elements? select all that apply. ni…
nitrogen oxygen bromine iodine chlorine
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16. compare and contrast how are a substance and a solution similar? ho…
16. Similarity: Macro - level uniform composition. Difference: Substance is pure, solution is a mixture. 17. Filtration for insoluble solid - liquid mixtures. Distillation for mix…
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14. explain explain the term phase as it relates to homogeneous and het…
14. In mixtures, a phase is a physically distinct part with uniform properties. Homogeneous mixtures have one phase; heterogeneous mixtures have two or more phases. 15. a. Homogen…
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3. list what type of properties can be used to separate mixtures?
Physical properties such as size, density, solubility, boiling - point, and magnetic properties.
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1. what is the ph of 0.25l of chicken soup? how about 0.5l? is it acidi…
1. The pH of 0.25L and 0.5L of chicken soup is approximately 5 - 6 and it is acidic. 2. The pH does not change with a greater volume of the substance as long as no acidic or basic…
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substance 3: solide de densité volumique de 1,7 g/cm³. des solutions in…
A. Éthanol B. Solution aqueuse d'acide acétique C. Solution aqueuse d'hydroxyde de sodium D. Glycérol E. Eau pure
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iodine dissolves in paint thinner which makes paint thinner a? polar so…
- Question 1: non polar solvent - Question 9: all of the above - Question 10: sucrose
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nacl table salt made up of na and cl ions dissolves in water but not in…
1. C. ionic compound 2. A. non polar compound
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question 3 what was the result of adding a base such as naoh to the buf…
- Question 3: There was minimal or almost no change. - Question 4: True - Question 5: True
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which of these ph solutions seen in the image below shows a neutral ph?…
Water
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which of the solutions in the image below do you think will have the lo…
A. Vinegar
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select the matching pairs. click the bottom right arrow to go to the ne…
polar - water, paint thinner - non polar
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a) when 2 moles of potassium carbonate and 1 mole of calcium chloride a…
a) $CaCl_2$; $K_2CO_3$ b) $K_2CO_3$; $CaCl_2$
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2. (a) co₂ and sio₂ are both covalent compounds. explain briefly why co…
(a) CO₂ is a gas due to weak intermolecular forces in simple - molecular structure; SiO₂ is a solid due to strong covalent bonds in giant covalent structure. (b)(i) Solid, due to …
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fill in the missing words note to students: for molar mass values, use …
$66$
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fill in the blanks within the following statements to describe the comp…
A fat or an oil forms when one glycerol molecule reacts with three fatty acid molecules. A fat is sometimes called a triglyceride because of its three - part structure, or a neutr…
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2. (a) co₂ and sio₂ are both covalent compounds. explain briefly why co…
$CO_2$ has weak intermolecular forces, $SiO_2$ has a giant covalent structure. ### 2. (b) (i)
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a) when 2 moles of potassium carbonate and 1 mole of calcium chloride a…
a) $CaCl_2$, $K_2CO_3$ b) $K_2CO_3$, $CaCl_2$
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which career is most concerned with the study of radioactive isotopes? …
B. nuclear chemist
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place the following items in order from lowest to highest ph milk soda …
1. Lemon juice 2. Soda 3. Milk 4. Pure water 5. Baking soda 6. Oven cleaner 7. Sodium hydroxide
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fill in the blanks to correctly complete the statements about the ph sc…
The pH scale ranges from 0 to 14. A solution of exactly pH 7 is the pH of water. pH 7, the pH of water, is a neutral pH because water releases an equal number of hydrogen ions (H+…
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grams of potassium hydroxide are expected to be produced if 3.1 g of po…
$3.7\ g$
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explain the ph scale by filling in the blanks on the following statemen…
The pH scale ranges from 0 to 14. Any solution with a pH below 7 is acidic. Even a small change in pH represents a large change in the proportional number of hydrogen and hydroxid…
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differentiate between an acid and a base by properly identifying the fo…
ACID: HCl, release hydrogen ions (H+) BASE: NaOH -> Na+ + OH-, milk of magnesia, substances that take up hydrogen ions, ammonia, substances that release hydroxide ions
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study the following phase diagram of substance x. use this diagram to a…
1. Solid 2. Sublime (change directly from solid to gas) 3. No phase change occurs
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2. (a) co₂ and sio₂ are both covalent compounds. explain briefly why co…
$CO_2$ has weak intermolecular forces in its simple - molecular form, while $SiO_2$ has a giant covalent structure with strong covalent bonds. ### 2(b)(i)
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study the following phase diagram of substance x. use this diagram to a…
Liquid It will vaporize. It will freeze.
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fill in the missing words write a balanced equation for the reaction of…
$8.44$
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consider a reaction of combustion of methane that produces carbon dioxi…
First case: 3, 6 Second case: 0.2, 0.4
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how did the development of the earliest idea about atoms differ from th…
It was based on the thoughts of an early philosopher.
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which atomic model was proposed as a result of j. j. thomsons work? the…
the plum pudding model
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which statement best describes john daltons use of creativity in his wo…
He reinterpreted and retested Joseph Proust's results.
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distinguish the difference between and ionic bond and a covalent bond b…
1. electrical 2. share 3. attraction 4. share 5. electrons
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fill in the blanks to explain why atoms interact. particles that carry …
1. ions 2. oppositely 3. electrons 4. stable 5. covalent
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which scientist provided a foundation for john daltons work on the atom…
Joseph Proust
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match each scientist to their discovery regarding the atom. dalton ruth…
Dalton - Atoms are indivisible. Rutherford - Atoms have a positive nucleus. Millikan - Electrons have a charge of - 1. Thomson - Atoms contain electrons.
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element # protons # neutrons # electrons mass number type your answer..…
| Element | # protons | # neutrons | # electrons | Mass Number | | ---- | ---- | ---- | ---- | ---- | | F | 9 | 10 | 9 | 19 | | N | 7 | 8 | 7 | 15 | | C | 6 | 8 | 6 | 14 |
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complete the sentences by filling in the blanks to explain how an atom …
An atom has a central nucleus. An atom has pathways about the nucleus called orbits. The shells are sometimes called energy levels. Subatomic particles called protons and neutrons…
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which of these did your answer include? dalton used creativity to modif…
All of the above options are correct if the question is asking about scientists using creativity in their experiments. If it's a single - choice question with an implicit 'only on…
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how many protons are in an atom of carbon - 14? helium 2 he 4.0026 boro…
6
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how many neutrons are in carbon - 14? helium 2 he 4.0026 boron 5 b 10.8…
8
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what kind of intermolecular forces act between a hydrogen fluoride mole…
London dispersion forces, dipole - dipole forces, hydrogen bonding
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21 multiple choice 4 points an atom has 20 protons and 20 electrons. ho…
20 (The second option in the multiple - choice list)
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how many neutrons are in uranium - 238 if it has 92 protons? 146 238 92…
146
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multiple choice 4 points how many protons are in an atom of nitrogen - …
7
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what kind of intermolecular forces act between a water molecule and a c…
ion - dipole force
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how many neutrons are in nitrogen-15? helium 2 he 4.0026 neon 10 ne 20.…
8
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14 multiple choice 4 points how many protons are in the isotope sulfur …
16
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what kind of intermolecular forces act between a fluorine (f2) molecule…
London dispersion force
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12 multiple choice 4 points a neutral atom has 12 protons. how many ele…
C. 12
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an atom has 82 protons and a mass number of 208. how many neutrons does…
A. 126
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what kind of intermolecular forces act between two carbon monoxide mole…
Dipole - dipole forces, London dispersion forces
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what kind of intermolecular forces act between two carbon monoxide mole…
London dispersion forces, dipole - dipole forces
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an atom has 19 protons and 20 neutrons. what is its mass number? 19 20 …
39
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9 multiple choice 1 point how many neutrons are in sulfur - 34? helium …
18
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8 multiple choice 1 point how many neutrons are in uranium - 238 if it …
A. 146
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how many neutrons are in carbon - 14? helium 2 he 4.0026 boron 5 b 10.8…
8
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what kind of intermolecular forces act between a methanol (ch3oh) molec…
Hydrogen bonding, London dispersion forces
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multiple choice 1 point what is cohesion in relation to water? water mo…
Water molecules sticking together
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which of the following best describes a polar covalent bond? a bond in …
A bond where electrons are shared unevenly between two atoms, resulting in a partial charge.
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3 multiple choice 1 point what is true about nonpolar covalent bonds? e…
Electrons are shared equally between atoms with similar electronegativities.
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multiple choice 1 point which of the following are molecules that have …
D. Isomer
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fill in the missing words note to students: for molar mass values, use …
One mole of water weighs $18.02$ grams. Molar mass of water is $18.02$ g/mol. One mole of zinc chloride weighs $136.28$ grams. Molar mass of zinc chloride is $136.28$ g/mol. One m…
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what kind of intermolecular forces act between a chloroacetylene (c2hcl…
Ion - dipole forces, London dispersion forces
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age of science 1747 andreas marggraf discovers that beet sugar is ident…
B. It documents key events in the sugar and sweetener industries
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multiple choice question orange juice fortified with calcium, yogurt pr…
B. functional foods
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multiple choice question when compared to plant foods, nutrient supplem…
D. phytochemicals
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fill in the missing words note to students: for molar mass values, use …
One mole of zinc metal weighs 65.38 grams. The molar mass of zinc is 65.38 g/mol. One mole of calcium metal weighs 40.08 grams. The molar mass of calcium is 40.08 g/mol. One mole …
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question 6 (2.5 points) molecules that contain carbon, hydrogen, and ox…
D. organic compounds
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multiple choice question in order to obtain nutrients and phytochemical…
C. eat a variety of "whole" and minimally processed foods
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molecules known as amino acids are the building blocks of proteins. 1) …
1) 1) True 2) 1) True 3) Away from the mid - line of the body
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multiple choice question which of these statements describes a key conc…
C. Since no naturally occurring food contains all nutrients in amounts your body needs, variety is important
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fill in the missing words mole of zinc contains 6.022x10^23 atoms of zi…
1 0.5
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1. (a) define the term polymerization. (b) state three characteristics …
(a) The process by which monomers combine to form polymers through chemical reactions. (b) Forward and reverse rates are equal; Concentrations of reactants and products are consta…
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multiple select question select all that apply choose the reasons it is…
A. Foods naturally contain beneficial combinations of nutrients and phytochemicals B. Nutrients from foods can sometimes be more available than nutrients from supplements D. Foods…
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water is often called the \universal solvent\ because many substances c…
polarity and cohesion
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multiple choice question the most natural and economical way to obtain …
C. a variety of "whole" and minimally processed foods
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question 7 what is a complimentary color scheme? using two colors oppos…
Using two colors opposite on the color wheel.
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hydrogen bonds in water molecules are formed between ____. o nuclei of …
Hydrogen and oxygen atoms of adjacent molecules
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rank the elements or compounds in the table below in decreasing order o…
D, C, Cr, Ar
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question 5 1 pts large bodies of water, such as lakes and oceans, do no…
Question 5: Water has a high heat capacity. Hydrogen bonds in water molecules are formed between: Hydrogen and oxygen atoms of adjacent molecules.
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question 2 anselm reyles artwork that is made up of 119 glowing neon tu…
Diagonal lines feel active like they have movement.
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1. (a) define the term polymerization. (b) state three characteristics …
(a) Polymerization is the combination of monomers to form polymers. (b) Equal forward and reverse rates; constant concentrations; dynamic at molecular level. (c) $CaSO_4$ coating …
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drop each substance in the correct category substance dissolved in wate…
Substance dissolved in water: $C_{6}H_{12}O_{6}(aq)$, $CO_{2}(aq)$, $NaHCO_{3}(aq)$ Substance in a liquid form (pure): $Br_{2}(l)$, $H_{2}O(l)$ Solid substance: $C_{6}H_{12}O_{6}(…
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rank the elements or compounds in the table below in decreasing order o…
D, C, B, A
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match the property of water with its description. choose choose choose …
High heat capacity - Water can absorb a lot of energy before changing temperature. Density - This causes solid water to float on liquid water. Cohesion - Water molecules stick to …
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rank the elements or compounds in the table below in decreasing order o…
1. $Al_2O_3$ 2. Substance with Lewis structure (ethanol) 3. $CO$ 4. $O_2$
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fill in the missing words in the reaction 2ag⁺(aq) + zn(s) → 2ag(s) + z…
reduced, oxidized, oxidizing agent, reducing agent, ionic equation
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fill in the missing words in redox reaction metals in their elemental f…
reducing; lose; oxidized
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select the correct answer. waters heat of vaporization is 2,257 joules/…
E. 25,300 J
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end of semester test takes place: mgbr₂(aq) + k₂co₃(aq) → mgco₃(s) + 2k…
D. 4.2 M
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rank the elements or compounds in the table below in decreasing order o…
1. $H_2O$ 2. $HgCl_2$ 3. $HCl$ 4. $H_2$
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fill in the missing words reactions that involve transfer of electrons …
Reactions that involve transfer of electrons between particles (atoms, molecules, ions) are called **redox** reactions. Reduction is the **gain** of electrons. Oxidation is the **…
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read the excerpt from levitt and dubners freakonomics. driving around t…
the size of his business
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read shakespeares sonnet 100 where art thou, muse, that thou forgetst s…
C. cdcd