Question 1

Which of the following statements best describes the relationship between matter, chemical elements, and atoms?

Accepted Answer

Atoms are the smallest unit of matter, and chemical elements are made up of atoms.

Question 2

A carbon atom has 6 protons, 6 neutrons, and 6 electrons. What is its atomic number and mass number?

Accepted Answer

Atomic number = $$6$$, Mass number = $$12$$

Question 3

Which subatomic particle has no electric charge and is found in the nucleus?

Accepted Answer

Neutron

Question 4

The atomic mass of an element is calculated as:

Accepted Answer

The sum of the number of protons and neutrons in the nucleus.

Question 5

Which of the following elements is NOT one of the six most abundant elements in living organisms (CHNOPS)?

Accepted Answer

Calcium

Question 6

How many valence electrons does a nitrogen atom (atomic number 7) have?

Accepted Answer

5

Question 7

According to the octet rule, why is neon (Ne) chemically unreactive?

Accepted Answer

Its valence shell is full of electrons.

Question 8

An oxygen atom has 8 electrons. How many more electrons does it need to fulfill the octet rule?

Accepted Answer

2

Question 9

Isotopes of an element differ in their:

Accepted Answer

Number of neutrons

Question 10

Carbon-13 and Carbon-14 are isotopes of carbon. What is true about them?

Accepted Answer

They have the same number of protons.

Question 11

A radioactive isotope has a half-life of 5,730 years. How many years must pass for a sample to decay to $$\frac{1}{4} of $$its original amount?

Accepted Answer

$$11,460$$ years

Question 12

Which of the following best describes a molecule?

Accepted Answer

A substance containing two or more chemically bound atoms.

Question 13

Which of the following is an example of an intermolecular bond?

Accepted Answer

The bond between two water molecules.

Question 14

Which of the following is a type of covalent bond?

Accepted Answer

Polar

Question 15

What makes a covalent bond nonpolar?

Accepted Answer

The bonded atoms share electrons equally.

Question 16

If a covalent bond is polar, what is true?

Accepted Answer

One of the atoms has a partial negative charge.

Question 17

Which of the following is considered a very weak non-covalent chemical bond?

Accepted Answer

Van der Waals bond

Question 18

What is the main difference between an anion and a cation?

Accepted Answer

An anion has more electrons than protons.

Question 19

Which of the following best describes an ionic bond?

Accepted Answer

Atoms of opposite charges attract each other.

Question 20

What property of the bond between a hydrogen atom and an oxygen atom in a water molecule makes it a polar bond?

Accepted Answer

O is more electronegative than H.

Atoms, Elements, and Atomic Structure: General Chemistry Study Notes

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