1c-Atomic structure

Question 1

What is the structure of an atom?

Answer 1

An atom consists of a nucleus containing protons and neutrons, surrounded by electrons in shells (energy levels).

Question 2

What are the charges and masses of protons, neutrons, and electrons?

Answer 2

Protons: Charge +1, mass 1
Neutrons: Charge 0, mass 1
Electrons: Charge -1, negligible mass (approximately 1/1836 of a proton).

Question 3

What is the atomic number and mass number?

Answer 3

Atomic Number (Z): The number of protons in an atom, which determines the element.
Mass Number (A): The total number of protons and neutrons in an atom.

Question 4

How do you calculate the number of neutrons?

Answer 4

Number of neutrons = Mass number - Atomic number.

Question 5

What are isotopes?

Answer 5

Isotopes are atoms of the same element with the same number of protons but different numbers of neutrons.

Example: Carbon-12 and Carbon-14.

Question 6

What is the relative atomic mass (Ar)?

Answer 6

Relative atomic mass is the weighted average mass of an atom compared to 1/12th of the mass of a carbon-12 atom.

Question 7

How do you calculate relative atomic mass from isotopes?

Answer 7

Ar = (Isotope 1 mass × % abundance) + (Isotope 2 mass × % abundance) / 100.

Question 8

What is a practical method for investigating atomic structure using models?

Answer 8

Use models (plastic balls and sticks) to represent protons, neutrons, and electrons.
Arrange electrons in shells around the nucleus.

Question 9

What are the results of investigating atomic structure using models?

Answer 9

Positive Result: Correct electron arrangement shows chemical properties of the element.
Negative Result: Incorrect placement of electrons results in misunderstanding of bonding behavior.