化学
化学反応、化学量論、分子構造、元素の性質。
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how many hydrogen bonds are found in a single molecule of water? option…
0
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6. make a rule: if you knew the number of valence electrons in a nonmet…
The valence of selenium is 2 (or 6, but commonly 2). ### Question 9:
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5. count: review the lewis diagrams you drew above. note that each elem…
(Table Filled): | Element | Symbol | # of valence electrons | Valence | Sum | |-----------|--------|------------------------|---------|-----| | Fluorine | F | 7 | 1 | 8 | | Hydrog…
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never remove chemicals, specimens or equipment from the lab area or cla…
A. True/Verdadera
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if i break a glass container, i should throw it in the trash? ¿si rompo…
False/falso
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when you finish working with chemicals, and other lab substances, alway…
D. wash your hands thoroughly with soap and water/ lavarse bien las manos con agua y jabón
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which of the following should not be worn during a laboratory activity?…
all of the above/ Todas las anteriores
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after completing an experiment, all chemical wastes should be... despué…
B. disposed of according to your teacher’s directions/ desechados de acuerdo con las instrucciones de su maestro
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approved eye protection devices (such as goggles) are worn in the lab..…
C. any time chemicals, heat or glassware are used./siempre que se utilicen productos químicos, calor o cristalería
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which of these is malleable? marble stone air wax
D. wax
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the type of bond formed from electron transfers the type of bond that w…
D. ionic
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the properties of valence electrons an atoms valence electron shell mul…
The option "determines its chemical reactivity." (the last option)
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bananas have a ph of 5. this means a banana has an excess of ______ ion…
B. $\text{H}^+$; acid
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an atom that has an electrical charge is called a(n) multiple choice el…
E. ion.
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sugar dissolves in coffee because multiple choice water is less dense t…
B. water is a good solvent.
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elements that differ in their ______ are known as isotopes. multiple ch…
E. neutron number
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which one of the following is the smallest unit of matter that has all …
C. atom
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a covalent bond occurs when multiple choice electrons are transferred f…
C. electrons are shared between two atoms to complete their valence shells.
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a(n) ______ can be defined as a substance that keeps ph within establis…
C. buffer
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given the chemical equation: $ce{c6h12o6 + 6 o2 -> 6 co2 + 6 h2o}$, ide…
B. $\ce{H_{2}O}$ is a product. D. $\ce{O_{2}}$ is a reactant.
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a tablet of benadryl (r), an antihistamine, has a mass of 0.48 g. it co…
\(5.0\)
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given the chemical equation: c₆h₁₂o₆ + 6 o₂ → 6 co₂ + 6 h₂o, identify w…
B. $\ce{H2O}$ is a product, D. $\ce{O2}$ is a reactant
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the subatomic particles that are found within the nucleus of an atom ar…
D. neutrons and protons.
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an element has an atomic number of 76. the number of protons and electr…
C. 76 protons and 76 electrons. (assuming the options are labeled A to E with the third option being C; if the original options have different labels, adjust accordingly, but base…
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what do lemons, tomatoes, and coffee all have in common chemically? mul…
C. They all release $\boldsymbol{H^+}$ ions in solution, making them acids.
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heartburn occurs when stomach acid escapes the stomach and burns the ti…
The baking soda is serving as a buffer to remove excess $\text{H}^+$ ions from stomach acid.
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the interaction among water molecules the figure below is depicting the…
B. hydrogen bonds.
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which of the following can be described as a molecule but not a compoun…
C. $\boldsymbol{O_2}$
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definition of isotopes isotopes of an atom differ in multiple choice th…
The option related to "Their atomic mass" (the last option, assuming the full question is about isotopes: Isotopes of an atom differ in their atomic mass).
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properties of subatomic particles which of the following statements abo…
The number and arrangement of electrons in an atom governs its chemical activity.
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the ph of pure water the ph of pure water is ______ because ______. mul…
B. 7.0; water contains an equal number of $\boldsymbol{H^+}$ ions and $\boldsymbol{OH^-}$ ions
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the number of protons defines an elemen all atoms of the same element h…
A. atomic number.
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water is a universal solvent because it... floats when frozen dissolves…
Dissolves most substances
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why does ice float? as water freezes, air becomes trapped between the h…
The correct option is: "As water freezes, it expands and its density decreases." (The second option in the list of choices provided in the problem)
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match each item with the correct base unit of the metric system used to…
powdered chemical - 3. Gram height of a tree - 1. Meter amount of water in a test tube - 4. Liter heat of a water bath - 2. Temperature
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mise en pratique 11 1 quel gaz a la plus grande réactivité chimique ? a…
B) Le dichlore ($\ce{Cl_2}$) ### Question 2
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how does temperature affect the state of water? select three correct an…
A. Water is a solid at temperatures lower than the melting point, C. Water is a gas at temperatures higher than the boiling point, D. Water is a liquid at temperatures between the…
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the elements from this section of the periodic table all belong to the …
C. period
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work together to create a rule to help to determine if a change is cons…
### Rule: - **Physical Change**: No new substance formed (changes in state, shape, size, or mixture without reaction). - **Chemical Change**: New substance formed (via reactions, …
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gold, silver, and aluminum are metals and are located to the left of th…
B. Low conductivity - does not allow the flow of electrical current and heat
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breaking glass vs battery generating electricity—watch the animation an…
### Breaking Glass #### What do you notice about the particles? The particles of the glass (molecules/atoms) remain the same in identity; they just change in arrangement (break in…
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breaking glass vs battery generating electricity—watch the animation an…
### Breaking Glass: #### What do you notice about the particles? The particles (molecules of glass) remain the same in identity; they just get separated into smaller pieces (the g…
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chopping wood vs burning wood—watch the animation and look at the befor…
### Chopping Wood: - **What do you notice about the particles?** The particles (wood) are just broken into smaller pieces; their chemical identity remains the same. - **Is this a …
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assuming no determinate errors, within what range are you at 95% confid…
Approximately \( 33.83\% \) ### Part d) For ethanoic acid (\( CH_3COOH \)), \( K_a = 1.8 \times 10^{-5} \), formula for pH of weak acid: \( pH = \frac{1}{2}(pK_a - \log c) \), whe…
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4. mientras lavaba la cristalería, mike le salpicó agua a evon. para ve…
NO ### Question 5
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click on the butter, watch the animation and look at the before and aft…
When butter melts, the particles (molecules) move more freely, their arrangement becomes less ordered (from solid - like close packing to liquid - like more spread - out), and the…
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1) a block of aluminum occupies a volume of 15.0 ml and weighs 40.5 g. …
s: 1. \( \boldsymbol{2.7 \, \text{g/mL}} \) 2. \( \boldsymbol{13.6 \, \text{g/mL}} \) 3. \( \boldsymbol{157.8 \, \text{g}} \) 4. \( \boldsymbol{\approx 8.92 \, \text{g/mL}} \) 5. …
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question one a) clearly distinguish between the following terms as appl…
### Part (a) #### i) End point and equivalence point - **End point**: The point in a titration where a visible change (like color change of an indicator) occurs, signifying that t…
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which of the following elements has 6 electrons in its outer shell? c) …
B) Oxygen
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read the passage from sugar changed the world. we all crave sweetness, …
B. New sources of sweetness use better techniques than the old sources did.
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vaporization is the process of a liquid becoming a gas. as a liquid hea…
Liquid to gas
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the passage describes a chemical reaction. read the passage. then, foll…
| Substance | Reactant | Product | |--|--|--| | carbon dioxide ($CO_2$) | | $\checkmark$ | | ethanol ($C_2H_6O$) | | $\checkmark$ | | glucose ($C_6H_{12}O_6$) | $\checkmark$ | |
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sublimation is when a solid gains energy and becomes a gas, skipping th…
Liquid
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condensation is when a gas loses energy and becomes a liquid. when a ga…
Droplets forming on a window after a hot shower
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question 7 (1 point) isotope4. a fictional element has two isotopes. is…
D. 34
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question 6 (1 point) elementname4. which element has the symbol of na? …
C. sodium
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question 9 (1 point) periodictable7. select all the period 4 transition…
C. Cr, D. Zn
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unit exam - states of matter and phase changes sublimation is when a so…
Freeze - drying food by turning ice directly into water vapor
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question 8 (1 point) listen periodictable6. select all the correct stat…
- It is a noble gas. - It does not like to lose or gain any electron. It tends to stay neutral.
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question 4 (1 point) periodictable4. select all the correct statement(s…
It is a nonmetal.
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question 5 (1 point) symbol5. the symbol for the element copper is ____…
Cu
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matter is made up of particles and can take the form of a solid, liquid…
The particles move freely.
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elementcompound1. select all the element(s) from the following substanc…
1. $\text{O}_2$, $\text{P}_4$, $\text{He}$
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question 10 (1 point) listen elementcompound3. select all the compound(…
B. PF₅, D. CaCO₃, E. CO₂
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question 1 (1 point) symbol5. the symbol for the element copper is ____…
E. Cu
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charge13. the charge of an atom is determined by which of the following…
A. number of electrons, C. number of protons
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question 9 (1 point) charge5. what is the charge on a silver ion that c…
C. +3
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question 8 (1 point) elementname8. which element has the symbol of sr? …
C. strontium
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question 3 (1 point) charge7. what is the charge on a sulfur ion that c…
- 2
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isotope6. element copper has two major isotopes, cu - 63 and cu - 65. t…
- Cu - 63 is more naturally abundant than Cu - 65. - Cu - 63 has fewer neutrons than Cu - 65.
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question 2 (1 point) massnumber1. a copper atom has 27 electrons and 34…
The mass number of an atom is the sum of the number of protons and neutrons. In a neutral atom, the number of electrons is equal to the number of protons. Given 27 electrons, ther…
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question 6 (1 point) listen massnumber6. an atom has 24 neutrons and a …
D. Ti
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question 1 (1 point) particle6. the charge of an atom is the same as th…
the number of protons minus the number of electrons
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question 5 (1 point) periodictable6. select all the correct statement(s…
C. It does not like to lose or gain any electron. It tends to stay neutral. D. It is a noble gas.
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matter is made up of particles and can take the form of a solid, liquid…
The particles move freely.
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matter is made up of particles and can take the form of a solid, liquid…
They move very fast.
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1. an element is a substance made of into another substance. it cannot …
1. An element is a substance made of only one - type of atom. It cannot be broken down into another substance. 2. A substance made of two or more different types of atoms that are…
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what kinds of substances can leaching carry downward through the soil? …
nutrients, pesticides, and synthetically based chemicals
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the selections states there have been changes in the way paper is made …
A. People today are careful to plant new trees to replace those that are cut down. E. Today there are strict laws to keep the lakes and rivers clean.
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how many significant figures are represented in each of the examples? a…
a. 4 b. 4 c. 4 d. 5 e. 2
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based on what you read, what is wastewater? a a type of thick glue used…
D. a kind of dirty water that is created when a paper mill makes paper
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before you start reading... here are the vocabulary words that will be …
contaminating radiation
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how does chemical weathering occur? by chemically breaking down rocks b…
by chemically breaking down rocks by water and gases
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which of these describes physical weathering? minerals in rocks being b…
rocks being broken down by freezing and thawing
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tree roots can break down rock into soil. which type of weathering is t…
Physical
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which drug contains the chemical thc and affects specific receptors in …
# Breve explicación: El THC (tetrahidrocannabinol) es el principal compuesto psicoactivo del cannabis, comúnmente conocido como marihuana. Este compuesto interactúa con receptores…
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2. how many cu atoms are there in 7.55 g cu?
$7.16\times 10^{22}$
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select all statements that are true about protons. they are negatively …
- They are located in the nucleus - They have a mass of 1 amu - The number of protons gives the atom its identity
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which of the following statements about electrons is correct? they are …
They are negatively charged and dictate chemical properties.
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poetry spenser invented a form called the spenserian _, a variation on …
Spenser: stanza; Petrarchan; 3; rhyme - scheme; archaic; grand; virtues Sidney: critical works; superior; captures Shakespeare: plays; sonnets
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famous poets and their sonnets francesco petrarch petrarchs poetry cent…
Francesco Petrarch: love Sir Thomas Wyatt: influenced Edmund Spenser: most; Cambridge; circle; poetry; sonnet; Italian; three; rhyme - scheme; archaic; elevated; virtues Sir Phili…
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1. the following are hypothetical elements (letters b - p) in the perio…
# Explanation: ## Paso 1: Interpretar configuraciones electrónicas Para identificar elementos a partir de configuraciones electrónicas, se usan las reglas de llenado de orbitales.…
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name ______________ sept 5 warm up use factor - label (dimensional anal…
$BaCl_2<BaF_2<MgCl_2$
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all of the chemical reactions that occur in the body are called metabol…
A. True
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9. what makes a homogeneous mixture unique? a. components can be visibl…
9. C. Components are uniformly distributed throughout 10. D. Protons and neutrons
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5. what are the three main states of matter? a. plasma, solid, and liqu…
5. D. Solid, liquid, and gas 6. C. Two or more elements chemically bonded together 7. A. Trail mix 8. B. Orbiting around the nucleus
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2. which statement best describes matter? a. anything that has weight o…
2. C. Anything that has mass and takes up space 3. A. Mass is the quantity of matter, while weight is a gravitational force 4. B. Something with uniform chemical properties and fi…
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infoseek engineering discussion notes 1. what is engineering? 2. what i…
1. Engineering is the application of scientific and mathematical knowledge to practical ends such as the design, manufacture, and operation of structures, machines, systems, and p…
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11. negatively charged subatomic particles in an atoms nucleus. a. elec…
11. a. Electron 12. c. pH 13. c. Solvent 14. b. Acids
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8. weak electrostatic bonds formed by the attraction of opposite charge…
8. a. Hydrogen Bonding 9. c. Atom 10. c. Proton