12 Protons 10 Electrons

Question: An ion has 12 protons, 14 neutrons, and 10 electrons. The symbol for the ion is….

Answer: A)24 Si 2-

B) 26 Ne 2+

C) 26 Mg 2+ <——-

D) 24 Si 2+

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Question: Calculate the atomic mass of element “X,” if it has 2 naturally occurring isotopes with the following masses:

X-45 44.8776 amu 32.88%

X-47 46.9443 amu 67.12%

Answer: A) 46.84 amu

B) 46.27 amu <——

C) 44.99 amu

D) 46.34 amu

E) 45.91 amu

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Question: Give the symbol for Magnesium.

Answer: Mg

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Question: Choose the pure substance from the list.

Answer: A) Salt Water

B) Pomegranate Juice

C) Coffee

D) CARBON DIOXIDE <——

E) A Casserole

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Question: Two or more substances in variable proportions, where the composition is constant throughout are:

Answer: A) A HOMOGENOUS MIXTURE <——

B) A heterogenous mixture

C) a compound

D) a crystalline solid

E) an element

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Question: Which of the following statements about the phases of matter is true?

Answer: A) Solids are highly compressible.

B) Gaseous substances have long-range repeating order.

C) Liquids have a large portion of empty volume between molecules.

D) IN BOTH SOLIDS AND LIQUIDS, THE ATOMS OR MOLECULES PACK CLOSELY TO ONE ANOTHER. <——

E) There is only one type of geometric arrangement that the atoms or molecules in any solid can adopt.

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Question: Isotopes differ in the number of…

Answer: A) protons and electrons

B) electrons

C) protons

D) gamma particles

E) neutrons

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Question: Water is an example of a….

Answer: A) a heterogenous mixture

B) an element

C) A COMPOUND <——

D) a homogenous mixture

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Question: An atom that has gained an electron is…

Answer: A) AN ANION (-) <—-

B) unlikely to be found in homogenous mixtures

C) a cation (+)

D) likely to behave exactly like the parent atom

E) electrically neutral

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Question: Molecules can be described as….

Answer: A) TWO OR MORE ATOMS CHEMICALLY JOINED TOGETHER <—-

B) homogenous mixtures

C) mixtures of two or more pure substances

D) heterogenous mixtures

E) mixtures of two or more elements that has a specific ration between components

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Question: An atom of 32P contains ________ electrons.

Answer: A) 15 <——

B) 47

C) 17

D) 27

E) 32

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Question: The mass number (A) is the number of _________ found in the nucleus of an atom.

Answer: A) neutrons

B) electrons

C) protons

D) protons and neutrons

E) PROTONS AND ELECTRONS <—-

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Question: A scientific law….

Answer: A) is subject to change via legal action

B) must have a mathematical formula

C) IS A BRIEF STATEMENT THAT SUMMARIZES PAST OBSERVATIONS AND MAKES PREDICTIONS <——

D) contains an explanation of observations

E) cannot be modified

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Question: An atom of 17 O contains ___________ protons.

Answer: A) 9

B) 8 <——

C) 25

D) 11

E) 17

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Question: Iodine is an example of….

Answer: A) a compound

B) a homogenous mixture

C) a heterogenous mixture

D) AN ELEMENT <——

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Question: The atomic number of an atom is 13 C is….

Answer: A) 7

B) 9

C) 6 <——

D) 13

E) 19

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Question: The atomic mass for silver is….

Answer: A) 47

B) 14

C) 28.09

D) 107.87 <——

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Question: Meter is a measure of…

Answer: A) volume

B) mass

C) time

D) length <——

E) temperature

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Question: Identify the element that has an atomic number of 20.

Answer: A) boron

B) CALCIUM <——

C) neon

D) zinc

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Question: When two elements form two different compounds, the masses of element B that combine with 1 g of element A can be expressed as a ratio of small whole numbers. Which law does this refer to?

Answer: A) Law of conversation mass

B) LAW OF MULTIPLE PROPORTIONS <——

C) Law of Modern Atomic Theory

D) Law of Definite Proportions

E) First Law of Thermodynamics

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Question: The cathode ray tube, as first studied by J.J. Thompson, showed that….

Answer: A) the protons of an atom are in the nucleus

B) the electron charge

C) the electrons are in empty space around the nucleus

D) THE NEGATIVELY CHARGED SUBATOMIC PARTICLES ARE EASILY RELEASED FROM A METAL SURFACE <—-

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Question: How many moles of potassium are contained in 150 grams of Potassium?

Answer: A) 7.90 moles

B) 3.83 moles <——

C) 10.0 moles

D) 4.85 moles

E) 0.720 moles

150g K x 1 mol K / 39.10 g K (Molar Mass) = _______.

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Question: How many significant figures are in the measurement 5.3 g?

Answer: A) 2 <—-

B) 5

C) 3

D) 4

E) 1

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Question: Calculate the mass (in grams) of 2.0 x 10^24 atoms of Hg.

Answer: A) 6.5 x 10^2 g <——

B) 1.5 x 10^2 g

C) 2.4 x 10^2 g

D) 3.2 x 10^2

E) 3.9 x 10^2

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Question: Round the following number to four significant figures and express the result in standard exponential notation: 0.35462

Answer: A) -0.3546

B) 35.46 x 10^2

C) 0.3546

D) 3.546 x 10^-1 <—-

E) 3.546 x 10^1

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Question: The conversion factor needed to convert mass of a pure substance to the same quantity in moles is…

Answer: A) atomic number

B) mass number

C) atomic mass

D) MOLAR MASS <—-

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Question: How many magnesium atoms are contained in 3.75 moles of Magnesium?

Answer: A) 1.23 x 10^24

B) 2.26 x 10^24 <——

C) 5.48 x 10^24

D) 6.50 x 10^24

E) 1.61 x 10^24

3.75 moles Mg x (6.022 x 10^23) / 1 mol = _______.

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Question: A propane molecule contains 3 atoms of carbon. The number 3 represents how many significant figures?

Answer: A) 1

B) 2

C) 3

D) infinite <——

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Question: What is the volume (in cm3) of a 9.37 g piece of metal with a density of 4.66 g/cm3?

Answer: A) .425

B) 2.01 <—-

C) 19.5

D) 6.65

E) none

v=m/d v= (9.37 g) / (4.66 g/cm3) = _________

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Question: What mass (in g) does 1.98 moles of Kr have?

Answer: A) 238 g

B) 120 g

C) 72 g

D) 105 g

E) 167 g <—-

1.98 moles Kr x 83.80 g / 1 mol = ________.

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Question: A piece of metal ore weighs 9.25 g. When a student places it into a graduated cylinder containing water, the liquid level rises from 21.25 mL to 26.47 mL. What is the density of the ore?

Answer: A) 0.349 g/mL

B) 2.86 g/mL

C) 1.77 g/mL <——

D) 0.564 g/mL

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Question: How many atoms of oxygen are in 2.50 moles of O2?

Answer: A) 4.52 x 10^24

B) 5.02 x 10^24

C) 1.51 x 10^24

D) 3.01 X 10^24 <——

E) 7.53 x 10^24

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Question: Which of the following are examples of intensive properties?

Answer: A) DENSITY <—-

B) volume

C) mass

D) none of the above

E) all of the above

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Question: A student performs an experiment to determine the density of a sugar solution. She obtains the following results: 1.71 g/mL, 1.73 g/ml, 1.67 g/mL, 1.69 g/mL. If the actual value for the density of the sugar solution is 1.40 g/mL, which statement below best describes her results?

Answer: A) her results are neither precise nor accurate.

B) her results are precise, but not accurate. <——

C) her results are accurate, but not precise.

D) her results are both precise and accurate.

E) it isn’t possible to determine with the info given.

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Question: Which of the following are examples of extensive properties?

Answer: A) color

B) volume

C) solubility

D) temperature

E) density

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Question: Which of the following contains the most atoms?

Answer: A) 10.0 g Kr

B) 10.0 g Cs

C) 10.0 g He <—-

D) 10.0 g Al

E) 10.0 g Ca

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Question: The mass of a proton is 1.67 x 10^-27 kg. What is the mass of a proton in milligrams? (1000 g = 1 kg, 1000 mg = 1 g)

Answer: A) 1.67 x 10^-24

B) 1.67 x 10^-21 <—-

C) 1.67 x 10^27

D) 1.67 x 10^18

1.67 x 10^-27 kg x 1000 g/ 1 kg x 1000 mg/ 1 g = _______.

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Question: Which of the following visible colors (wavelength) of light has the highest frequency?

Answer: A) green

B) blue <——

C) yellow

D) red

E) orange

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Question: Place the following types of electromagnetic radiation in order of decreasing energy.

Answer: X-Rays > microwaves > radio waves

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Question: Electromagnetic radiation with a wavelength of 425 nm appears as violet light to the human eye. The frequency of this light is….

Answer: 7.06 x 10^14

V=C/Wave (3.00 x 10^8 m/s) / (425 nm)

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Question: The vertical height of a wave is called…

Answer: A) wavelength

B) amplitude <——

C) frequency

D) area

E) median

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Question: The distance between adjacent crests is called…

Answer: A) wavelength <—-

B) amplitude

C) frequency

D) area

E) median

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Question: Which of the following statements is true?

Answer: A) Part of the Bohr model proposed that electrons in the hydrogen atom are located with random amounts of energy.

B) atoms emit excess energy by reducing the energy level of protons in the nucleus.

C) moving an atom to an excited state requires electrical energy.

D) THE EMISSION SPECTRUM OF A PARTICULAR ELEMENT IS ALWAYS THE SAME AND CAN BE USED TO IDENTIFY THE ELEMENT. <——

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Question: Which go the following transitions (in a hydrogen atom) represent emission of the longest wavelength photon?

Answer: A) n=5 to n=4 <——

B) n=3 to n=5

C)n=1 to n=3

D) n=4 to n=2

E) n=3 to n=1

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Question: On the electromagnetic spectrum, visible light is immediately between two other wavelengths. Name them.

Answer: infrared and ultraviolet rays

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Question: Place the following types of electromagnetic radiation in order of increasing frequency.

Answer: ultraviolet, x-rays, gamma rays

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Question: The number of cycles that pass through a stationary point is called…

Answer: A)wavelength

B) amplitude

C) frequency <——

D) area

E) median

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Question: Place the following types of electromagnetic radiation in order of increasing wavelength.

Answer: Gamma rays, visible light, radio waves

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Question: When waves of equal amplitude from two sources are out of phase when they interact it is called

Answer: destructive interference

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Question: How many orbitals are there of the 4f type?

Answer: 7

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Question: An orbital is best defined as…

Answer: a region in space which there is a high probability of finding an electron

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Question: States that each orbital can hold a max of 2 electrons with opposing spins.

Answer: The Pauli Exclusion Principle

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Question: Orbitals of the same energy first fill the singly with electrons with parallel spins before pairing.

Answer: Hund’s Rule

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Question: Made of only one type of particle, composition does not vary.

Answer: pure substance… ex. helium, water, salt

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Question: Composed of two or more particles and vary from one another.

Answer: mixture… ex. sweet tea

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Question: Composed of two or more elements.

Answer: compound

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Question: cannot be chemically broken down into simpler substances.

Answer: element

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Question: Who came up with scientific method?

Answer: Lavoiser

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Question: a brief statement that summarizes past observations and predicts future ones

Answer: scientific law

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Question: “In a chemical reaction, matter is neither created nor destroyed.”

Answer: Law of conversation mass

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Question: explains why nature does what it does but not WHAT it does

Answer: theories

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Question: theory proposed by john dalton

Answer: atomic theory

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Question: “All samples of a given compound, regardless of their source or how they were prepared, have the same proportions to their constituent elements.”

Answer: Law of definite proportions

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Question: “When 2 elements form two diff compounds, the masses of element B that combine with 1 g of element A can be expressed as a ratio of whole numbers.”

Answer: Law of multiple proportions

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Question: —Each element is composed of atoms

—All atoms of a given element have the same mass and other properties that distinguish them from the atoms of other elements.

—Atoms combine in whole number ratios to form compounds.

—Atoms of one element cannot change into atoms of another element. Only change when bound to other atoms.

Answer: Dalton’s Atomic Theory

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Question: Who constructed the cathode ray tube experiment and what were the results?

Answer: J.J Thompson. He found that a beam of particles traveled from the neg electrode to the pos. He discovered the electron, a neg charged particle.

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Question: What did the Plum Pudding Model suggest?

Answer: That neg charged particles were held within a pos charged sphere.

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Question: What was the gold foil experiment and who constructed it?

Answer: Rutherford. Proved that Thompson’s plum pudding theory was wrong. Particles penetrated the foil, some deflected.

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Question: Who developed nuclear theory?

Answer: Rutherford.

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Question: Who discovered neutrons, the unaccounted mass from Rutherford’s experiment?

Answer: Chadwick

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Question: Isotope symbolization??

Answer: A/Z X

A= mass #

Z= atomic #

X= chemical symbol

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Question: atoms that gain or lose electrons

Answer: ions

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Question: negatively charged ions (+)

Answer: cation

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Question: positively charged ions (-)

Answer: anion

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Question: these type of properties do not rely on the amount of the substance… ex. density

Answer: intensive properties

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Question: these type of properties DO rely on the amount of the substance… ex. mass

Answer: extensive properties

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Question: formula for density??

Answer: density = mass/volume

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Question: “Energy is neither created nor destroyed.”

Answer: Law of conservation energy

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Question: Orbital filling order??

Answer: 1s2 2s2 2p6 3s2 3p6 4s2 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s 5f14 6d107p6

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Question: A covalent bond is best described as?

Answer: The sharing of electrons between atoms.

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Question: Write the formula for Magnesium Nitrite.

Answer: Mg(NO2)2

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Question: Calculate the mass percent composition of sulfur in Al2(SO4)3.

Answer: Al=2(26.98) + S=3(32.07) + O=12(16.00) = Formula Mass = 342.17

Mass % of S = 3(32.07) / 342.17 (MM) x 100% = 28.12%

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Question: How many molecules of N2O4 are in 76.3 g of N204?

Answer: 76.3 g N204 x 1 mol N2O4 / 92.04 (MM) x 6.022x10^23 / 1 mol = 4.99 x 10^23

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Question: A double covalent bond contains how many pairs of electrons?

Answer: 2 pairs

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Question: Identify the weakest bond

Answer: a single covalent bond

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