Question 1

Which of the following best describes a heterogeneous mixture?

Accepted Answer

A mixture in which the components are not evenly distributed and can be visually distinguished, such as salad dressing.

Question 2

Which subatomic particle has a relative mass close to 1 amu and is found in the nucleus of an atom?

Accepted Answer

Neutron

Question 3

Which of the following is an example of a physical change?

Accepted Answer

Melting ice

Question 4

Which group on the periodic table is known as the noble gases?

Accepted Answer

Group 8A

Question 5

Convert $$0.00045$$ meters to scientific notation.

Accepted Answer

$$4.5 	imes 10$$^{-4}$$

Question 6

A sample has a mass of $$12.0 g $$and a volume of $$8.0 mL. $$What is its density?

Accepted Answer

$$1.5 g/mL$$

Question 7

Which of the following is the correct formula to convert Celsius to Fahrenheit?

Accepted Answer

$$F = 1.8C + 32$$

Question 8

Which of the following atomic symbols represents an isotope of $$^{14}_{6}C$$?

Accepted Answer

$$^{12}_{6}C$$

Question 9

How many valence electrons does sulfur (S) have?

Accepted Answer

6

Question 10

Which of the following describes the trend of atomic size across a period from left to right?

Accepted Answer

Atomic size decreases due to increased nuclear charge.

Question 11

Which radioactive decay process emits a particle with a charge of $$+1$$ and mass number $$0$$?

Accepted Answer

Positron emission

Question 12

A radioactive isotope has a half-life of $$6$$ hours. If you start with $$80 g$$, how much remains after $$18$$ hours?

Accepted Answer

$$10 g$$

Question 13

Which isotope is most commonly used in PET scans?

Accepted Answer

$$^{18}F$$

Question 14

Which type of nuclear reaction powers the sun?

Accepted Answer

Nuclear fusion

Question 15

What is the charge of the copper ion in $$CuCl_2$$?

Accepted Answer

$$+2$$

Question 16

Which element is a metal and located on the left side of the periodic table?

Accepted Answer

Sodium (Na)

Question 17

Which of the following is a correct electron configuration for magnesium ($$Z=12$$)?

Accepted Answer

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

Question 18

If an atom has $$17$$ protons and $$18$$ electrons, what is its charge?

Accepted Answer

$$-1$$

Question 19

Which of the following is a correct definition of density?

Accepted Answer

Density is the mass per unit volume.

Question 20

Which type of bond is formed when electrons are transferred from one atom to another?

Accepted Answer

Ionic bond

Chem 101 Exam 1 Study Guide: Chapters 1–5.3 (Atoms, Matter, Measurement, Nuclear Chemistry, and Ionic Compounds)

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