Module 2 Atomic structure and Isotopes

Question 1

What was stated in Dalton’s atomic theory?

Answer 1

• Atoms are tiny particles made up of elements.
• Atoms cannot be divided.
• All the atoms in an element are the same.
• Atoms of one element are different to those of other elements.

Question 2

What did Thompson discover about electrons?

Answer 2

• They have a negative charge.
• They can be deflected by magnet and electric field.
• They have a very small mass.

Question 3

Explain the plum pudding model.

Answer 3

Atoms are made up of negative electrons moving around in a sea of positive charge.

Question 4

What were the Rutherford’s proposal after the gold leaf experiment?

Answer 4

• Most of the mass and positive charge of the atom are in the nucleus.
• Electrons orbit the nucleus.
• Most of atom’s volume is the space between the nucleus and electrons.
• Overall positive and negative charges must bakance.

Question 5

Define isotope.

Answer 5

Atoms of the same element with different number of atoms.

Question 6

Why do different isotopes of the same element react in the same way?

Answer 6

• Neutrons have no impact on the chemical reactivity.
• Reactions involve electrons, isotopes have the same number of electrons in the same arrangement.

Question 7

What are ions?

Answer 7

Charged particles that is formed when an atom loses or gains electrons.

Question 8

What is the charge of the ion when electrons are gained?

Answer 8

Negative.

Question 9

Define relative atomic mass.

Answer 9

The weighted mean mass of an atom of an element compared with one twelfth of the mass of an atom of carbon-12.