Atomic structure & bonding

Question 1

What is an atom?

Answer 1

An atom is the smallest unit of matter that makes up everything around you. It has a tiny center called a nucleus, made of protons and neutrons, with electrons orbiting around it.

Question 2

What is a molecule

Answer 2

substance that still has all the properties of that substance. For example, a water molecule (H₂O) is made up of two hydrogen atoms and one oxygen atom bonded together.

Question 3

what is meant by the term atomic number

Answer 3

The atomic number is the number of protons in the nucleus of an atom. It determines the identity of an element and its position on the periodic table. For example, the atomic number of hydrogen is 1 (because it has 1 proton), and the atomic number of carbon is 6 (because it has 6 protons).

Question 4

what is meant by the term mass number

Answer 4

The mass number is the total number of protons and neutrons in the nucleus of an atom. It gives an idea of the atom’s mass. For example, if an atom has 6 protons and 6 neutrons, its mass number would be 12. Unlike the atomic number, the mass number is not listed on the periodic table because it can vary depending on the number of neutrons (different isotopes of an element have different mass numbers).

Question 5

what is meant by the term isotopes

Answer 5

Isotopes are different forms of the same element that have the same number of protons but different numbers of neutrons. This means they have the same atomic number but different mass numbers. Isotopes of an element have similar chemical properties but can have different physical properties, such as stability or radioactivity.

For example:

Carbon-12 has 6 protons and 6 neutrons.
Carbon-14 has 6 protons and 8 neutrons.
Both are isotopes of carbon, but Carbon-14 is radioactive, while Carbon-12 is stable.

Question 6

what is meant by the term relative atomic mass

Answer 6

Relative atomic mass is the average mass of an element’s atoms, considering all its natural isotopes, compared to one-twelfth of the mass of a carbon-12 atom.

Question 7

how are ions former by electron loss or gain?

Answer 7

Ions are formed when atoms gain or lose electrons:

Loss of electrons creates a positively charged ion (cation).
Gain of electrons creates a negatively charged ion (anion).
The number of protons stays the same, but the change in electrons results in a charge.

Question 8

zinc

Answer 8

Zn²⁺

Question 9

silver

Answer 9

Ag⁺

Question 10

iron

Answer 10

Fe²⁺Fe³⁺

Question 11

copper

Answer 11

Cu²⁺

Question 12

lead

Answer 12

Pb²⁺

Question 13

hydrogen

Answer 13

H⁺

Question 14

hydroxide

Answer 14

OH⁻

Question 15

ammonium

Answer 15

NH₄⁺

Question 16

carbonate

Answer 16

CO₃²⁻

Question 17

nitrate

Answer 17

NO₃⁻

Question 18

sulfate

Answer 18

SO₄²⁻

Question 19

the difference between covalent and ionic bonds.

Answer 19

Ionic: Forms between a metal and a non-metal, where electrons are transferred (e.g., NaCl).
Covalent: Forms between two non-metals, where electrons are shared (e.g., H₂O).

Question 20

hydrogen ( H⁺ ) sulphate (SO₄²⁻) compound

Answer 20

H₂SO₄