Q: A student needs to convert $$5.00 m$^3 to cm$^3. $$Which conversion factor should be used, and what is the correct answer?

Multiply by $$1 \times 10^6$; 5.00$$ \times $$10^6 cm$^3$$

Question 1

A student observes that when magnesium metal is burned in air, a white powder forms and the mass increases. Which statement best classifies this observation according to the scientific method?

Accepted Answer

It is an observation because it describes what was seen during the experiment.

Question 2

Which of the following best describes the relationship between the variables in the equation $$y = kx$$ when graphed?

Accepted Answer

y and x have a direct relationship.

Question 3

Convert $$0.000456 to $$scientific notation with the correct number of significant figures.

Accepted Answer

$$4.56 	imes 10$$^{-4}$$

Question 4

A student multiplies $$2.34 (3 $$sig figs) by $$0.020 (2 $$sig figs). What is the correct answer, with the proper number of significant figures?

Accepted Answer

$$0.047$$

Question 5

A rectangular block has a length of $$12.0 cm$$, width of $$3.00 cm$$, and height of $$2.0 cm. $$What is its volume, reported with the correct number of significant figures?

Accepted Answer

$$72 cm$^3$$

Question 6

A sample of ethanol has a mass of $$78.5 g $$and a volume of $$100.0 mL. $$What is its density?

Accepted Answer

$$0.785$$ 	ext{ g/mL}$

Question 7

Which of the following is a chemical change?

Accepted Answer

Burning a piece of paper.

Question 8

A mixture of sand and salt is best classified as which type of matter?

Accepted Answer

Heterogeneous mixture

Question 9

A reaction starts with $$12.0 g of $$carbon and $$32.0 g of $$oxygen, producing carbon dioxide. According to the law of conservation of mass, what is the total mass of carbon dioxide produced?

Accepted Answer

$$44.0 g$$

Question 10

Convert $$25.0$$ $$^	ext{o}C to $$Kelvin.

Accepted Answer

$$298.15$$ 	ext{ K}$

Question 11

How much heat (in Joules) is required to raise the temperature of $$50.0 g of $$water from $$20.0$$ $$^	ext{o}C to$$ $$80.0$$ $$^	ext{o}C$$? (Specific heat of water $$c = 4.18 J/g$^	ext{o}C)$$

Accepted Answer

$$12,540$$ 	ext{ J}$

Question 12

Which subatomic particle has a mass of approximately $$1$$ amu and a charge of $$+1$$?

Accepted Answer

Proton

Question 13

An atom has $$17$$ protons, $$18$$ neutrons, and $$18$$ electrons. What is its net charge?

Accepted Answer

$$-1$$

Question 14

Chlorine has two main isotopes: $$^{35}Cl ($$mass = $$34.97$$ amu, abundance = $$75.8\%) $$and $$^{37}Cl ($$mass = $$36.97$$ amu, abundance = $$24.2\%). $$What is the average atomic mass of chlorine?

Accepted Answer

$$35.45$$ 	ext{ amu}$

Question 15

Which of the following correctly describes the trend in atomic radius across a period from left to right?

Accepted Answer

Atomic radius decreases.

Question 16

Which electron configuration represents a neutral atom of sodium ($$Z=11$$)?

Accepted Answer

$$1s^2$$ $$2s^2$$ $$2p^6$$ $$3s^1$$

Question 17

Which principle states that no two electrons in the same atom can have the same set of four quantum numbers?

Accepted Answer

Pauli Exclusion Principle

Question 18

Which of the following elements has the highest ionization energy?

Accepted Answer

Fluorine ($$F)$$

Question 19

A student needs to convert $$5.00 m$^3 to cm$^3. $$Which conversion factor should be used, and what is the correct answer?

Accepted Answer

Multiply by $$1 	imes 10^6$; 5.00$$ 	imes $$10^6 cm$^3$$

Question 20

Which of the following statements about the electromagnetic spectrum is correct?

Accepted Answer

As frequency increases, energy increases.

Introduction to Chemistry: Scientific Method, Measurement, Matter, Atomic Structure, and Electrons

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