Question 1

Which of the following best describes a compound?

Accepted Answer

A substance made of two or more elements chemically combined in fixed proportions.

Question 2

Which subatomic particle has a negative charge and is found outside the nucleus?

Accepted Answer

Electron

Question 3

Which of the following is a chemical change?

Accepted Answer

Iron rusting in moist air

Question 4

Which phase transition links the solid and gas phases directly, bypassing the liquid phase?

Accepted Answer

Deposition

Question 5

How many significant digits are in the number 0.00450?

Accepted Answer

3

Question 6

Express the number 0.00072 in scientific notation.

Accepted Answer

$$7.2 	imes 10$$^{-4}$$

Question 7

A calculation involves multiplying $$2.50 (3 $$sig figs) by $$0.040 (2 $$sig figs). What is the correct answer, rounded to the proper number of significant digits?

Accepted Answer

$$0.10$$

Question 8

Convert $$25^	ext{\circ}C to $$kelvin. (Round to the nearest whole number.)

Accepted Answer

$$298 K$$

Question 9

Which of the following is NOT a fundamental SI measurement concept?

Accepted Answer

Density

Question 10

An atom has an atomic number $$Z = 17$$ and a mass number $$A = 35. $$How many neutrons does it have?

Accepted Answer

$$18$$

Question 11

Which of the following is the correct isotope notation for an atom with $$Z = 6$$ and $$A = 14$$?

Accepted Answer

$$^{14}_{6}	ext{C}$$

Question 12

A sodium ion ($$	ext{Na}^+) $$has an atomic number $$Z = 11. $$How many electrons does it have?

Accepted Answer

$$10$$

Question 13

Which group on the periodic table contains the alkali metals?

Accepted Answer

Group 1

Question 14

How many electrons can fit in the second shell ($$n=2) of an $$atom?

Accepted Answer

$$8$$

Question 15

What is the electron configuration for neon ($$	ext{Ne}$$, $$Z=10$$)?

Accepted Answer

$$1s^2$$\ $$2s^2$$\ $$2p^6$$

Question 16

Why do atoms gain or lose electrons?

Accepted Answer

To achieve a stable electron configuration, often resembling that of a noble gas.

Question 17

What ionic charge would a monatomic cation from Group 2 of the periodic table have?

Accepted Answer

$$+2$$

Question 18

Which of the following elements is a non-metal based on its position on the periodic table?

Accepted Answer

Chlorine

Question 19

A sample contains a mixture of sand and salt. Which method would best separate these substances?

Accepted Answer

Filtration followed by evaporation

Question 20

A patient’s body temperature is measured at $$39^	ext{\circ}C. $$What is this temperature in kelvin?

Accepted Answer

$$312 K$$

CHEM 1120 Exam I Study Guide: Foundations of Chemistry

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