Question 1

A neutral atom of sodium (Na) has an atomic number of 11 and an atomic mass of 23. How many neutrons does it have?

Accepted Answer

12

Question 2

Which of the following best explains why water is considered a polar molecule?

Accepted Answer

Oxygen has a stronger pull on electrons, creating a partial negative charge on the oxygen and a partial positive charge on the hydrogens.

Question 3

Which of the following is a correct electron configuration for an atom with 10 electrons?

Accepted Answer

2 electrons in the first energy level, 8 electrons in the second energy level

Question 4

Which of the following best describes a covalent bond?

Accepted Answer

A bond formed by the sharing of electrons between two atoms.

Question 5

If a solution has a pH of 3, which of the following statements is true?

Accepted Answer

It is acidic.

Question 6

Which property of water allows it to absorb large amounts of heat with only a slight change in temperature?

Accepted Answer

High specific heat capacity

Question 7

A molecule of NaCl is formed when:

Accepted Answer

Sodium donates an electron to chlorine, forming oppositely charged ions that attract each other.

Question 8

Which of the following best explains why water is called the 'universal solvent'?

Accepted Answer

Its high polarity allows it to dissolve many ionic and polar substances.

Question 9

How many protons, neutrons, and electrons are present in a neutral atom of Carbon-14?

Accepted Answer

6 protons, 8 neutrons, 6 electrons

Question 10

Which of the following is an example of a molecule held together by nonpolar covalent bonds?

Accepted Answer

Oxygen gas (O$$_2)$$

Question 11

Which of the following best describes the role of hydrogen bonds in water?

Accepted Answer

They form between water molecules, giving water its unique properties.

Question 12

A student mixes 10 g of salt into 100 mL of water. In this solution, which is the solute and which is the solvent?

Accepted Answer

Salt is the solute; water is the solvent.

Question 13

Which of the following best explains why ice floats on liquid water?

Accepted Answer

Hydrogen bonds cause water molecules in ice to be more spread out, making ice less dense than liquid water.

Question 14

Which of the following is true about ions?

Accepted Answer

Ions are formed when atoms gain or lose electrons.

Question 15

Which of the following best describes the difference between a molecule and a compound?

Accepted Answer

A molecule is a group of atoms held together by covalent bonds, while a compound is a substance made of two or more different elements bonded together.

Question 16

Which of the following best describes the function of coefficients in a chemical equation?

Accepted Answer

They indicate the number of molecules or formula units involved in the reaction.

Question 17

A solution has a pH of 9. Which of the following statements is correct?

Accepted Answer

The solution is basic and has more OH$$^-$$ ions than H$$^+$$ ions.

Question 18

Which of the following is a real-life example of evaporative cooling?

Accepted Answer

Sweating during exercise

Question 19

If an atom has 8 electrons, how are they distributed in its energy levels?

Accepted Answer

2 in the first level, 6 in the second level

Question 20

Which of the following best explains why water forms a meniscus in a graduated cylinder?

Accepted Answer

Adhesion between water molecules and the glass

123

Study Guide - Practice Questions

Study Guide - Flashcards