Q: How many atoms are present in $$32.066 g of $$sulfur? (Molar mass of S = $$32.066 g/$$mol, $$1$$ mol = $$6.022 \times 10$$^{23}$$ atoms)

$$6.022 \times 10$$^{23}$$ atoms

Question 1

Which of the following best describes a physical change?

Accepted Answer

Water boiling to form steam

Question 2

Which of the following is a mixture?

Accepted Answer

Air

Question 3

A student measures the mass of a sample as 0.00450 g. How should this value be expressed in scientific notation?

Accepted Answer

$$4.50 	imes 10$$^{-3}$$ g$

Question 4

Which of the following statements about elements and compounds is correct?

Accepted Answer

Elements cannot be broken down into simpler substances by chemical means.

Question 5

Convert 212°F to degrees Celsius using the appropriate formula.

Accepted Answer

$$100^\circ \mathrm{C}$$

Question 6

A sample of gasoline has a density of $$0.68 \ \mathrm{g/cm^3$}. $$What is the mass, in grams, of $$10.0$$ gallons of gasoline? (1 gal = 3.785 L, 1 L = 1000 cm³)

Accepted Answer

$$25,700 g$$

Question 7

Which of the following is a correct statement about the atomic number of an element?

Accepted Answer

It is equal to the number of protons in the nucleus.

Question 8

How many atoms are present in $$32.066 g of $$sulfur? (Molar mass of S = $$32.066 g/$$mol, $$1$$ mol = $$6.022 	imes 10$$^{23}$$ atoms)

Accepted Answer

$$6.022 	imes 10$$^{23}$$ atoms

Question 9

Which of the following best describes the difference between a metal and a nonmetal?

Accepted Answer

Metals are good conductors of electricity, while nonmetals are poor conductors.

Question 10

Which of the following is the correct electron configuration for a neutral atom of tin (Sn, atomic number 50)?

Accepted Answer

$$[Kr] \ 5s^2$ \ 4d$$^{10}$$ \ 5p^2$

Question 11

A medication is prescribed at a dosage of $$5.0 mg $$per kg of body weight. What is the required dose, in mg, for a $$100.0 kg $$patient?

Accepted Answer

$$500 mg$$

Question 12

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes of an element have the same number of protons but different numbers of neutrons.

Question 13

Which of the following is the correct relationship between mass, volume, and density?

Accepted Answer

$$d = \frac{m}{V}$$

Question 14

Which of the following best describes the trend in atomic radius across a period in the periodic table?

Accepted Answer

Atomic radius decreases from left to right across a period.

Question 15

Which of the following is the correct formula to convert a temperature from Celsius to Kelvin?

Accepted Answer

$$K = ^\circ C + 273.15$$

Question 16

Which of the following is the maximum number of electrons that can occupy a single orbital?

Accepted Answer

2

Question 17

Which of the following best explains why elements in the same group of the periodic table have similar chemical properties?

Accepted Answer

They have the same number of valence electrons.

Question 18

Which of the following is a correct statement about the law of conservation of mass?

Accepted Answer

The total mass of reactants equals the total mass of products in a chemical reaction.

Question 19

Which of the following is the correct value for Avogadro's number?

Accepted Answer

$$6.022 	imes 10$$^{23}$$

Question 20

Which of the following best describes a chemical property?

Accepted Answer

The ability of iron to rust when exposed to air

CHE121 Exam 1 Study Guide

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