Question 1

Which of the following statements best describes an element?

Accepted Answer

A substance that cannot be broken down into simpler substances by chemical means and is made of only one type of atom.

Question 2

Using the periodic table, what is the atomic number of carbon and what does it represent?

Accepted Answer

6; it represents the number of protons in a carbon atom.

Question 3

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

Accepted Answer

$$11$$

Question 4

Which of the following best explains the difference between a polar and a non-polar covalent bond?

Accepted Answer

Polar covalent bonds involve unequal sharing of electrons, resulting in partial charges, while non-polar covalent bonds involve equal sharing of electrons.

Question 5

Which of the following is a correct example of an ionic bond?

Accepted Answer

The bond between sodium (Na) and chlorine (Cl) in table salt ($$NaCl)$$

Question 6

If an atom has 8 protons, 8 neutrons, and 10 electrons, what is its charge?

Accepted Answer

$$-2$$

Question 7

Which of the following best describes a compound?

Accepted Answer

A substance formed when two or more different elements are chemically bonded together in fixed proportions.

Question 8

What type of chemical bond is responsible for the structure of water ($$H_2O$$), and why is it important for life?

Accepted Answer

Polar covalent bond; it allows water molecules to form hydrogen bonds, which are crucial for many biological processes.

Question 9

Which of the following is NOT a subatomic particle found in atoms?

Accepted Answer

Molecule

Question 10

A cell is described as the smallest biological unit that can perform all activities required for life. Which property of cells is most directly related to their chemical organization?

Accepted Answer

Cells are organized collections of many different chemicals that allow them to carry out specialized functions.

Question 11

Which of the following statements about the periodic table is correct?

Accepted Answer

The atomic number represents the number of protons in an atom.

Question 12

Which of the following best explains why ionic bonds form between sodium (Na) and chlorine (Cl)?

Accepted Answer

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

Question 13

Which of the following is a common non-bond chemical interaction that occurs in organic molecules?

Accepted Answer

Hydrogen bonding

Question 14

Which of the following best describes the relative strength of chemical bonds in biological systems?

Accepted Answer

Covalent bonds are generally stronger than ionic bonds and hydrogen bonds.

Question 15

A molecule of $$CO_2$$ contains two double bonds. How many electrons are shared between the carbon and oxygen atoms in each double bond?

Accepted Answer

$$4$$

Question 16

Which of the following scenarios best illustrates the concept of a compound?

Accepted Answer

A plant containing carbon, hydrogen, oxygen, and nitrogen atoms chemically bonded together.

Question 17

If the number of protons in an atom changes, what is the result?

Accepted Answer

The atom becomes a different element.

Question 18

Which of the following best describes how polar molecules interact with their surroundings?

Accepted Answer

They interact strongly with other polar molecules and water due to partial charges.

Question 19

A hydrogen atom has 1 proton and 1 electron. If it loses its electron, what is its charge?

Accepted Answer

$$+1$$

Chemistry Foundations for Biology: Elements, Atoms, and Chemical Bonds

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