• Atomic Structure

Question 1

What does every atom contain?

Answer 1

• Positively charged nucleus composed of protons and neutrons
• Electrons that surround the nucleus

Question 2

How are electrons held in the in the atom?

Answer 2

• Electrons have a negative charge.
• Nucleus has a positive charge.
This means that electrons are held in the atom by the electrostatic force of attraction between them and the nucleus.

Question 3

What force holds the electrons in the atom?

Answer 3

Electrostatic force

Question 4

What did Rutherford’s investigations show about the the nucleus?

Answer 4

• Nucleus contains most of the mass of the atom.

* Diameter is 0.00001 times the diameter of a typical atom.

Question 5

How does mass differ between electrons, protons and neutrons?

Answer 5

• Electron has a smaller mass than the proton or neutron.

* Proton and neutron have almost equal mass

Question 6

How does charge differ between electrons, protons and neutrons?

Answer 6

• Electron has equal and opposite charge to the proton.

* Neutron is uncharged.

Question 7

What is an isotope?

Answer 7

Atoms with the same number of protons and different numbers of neutrons.

Question 8

What is the nucleon number/mass number?

Answer 8

Total number of protons and neutrons in an atom.

Question 9

What is a nucleon?

Answer 9

A proton or a neutron in the nucleus.

Question 10

How are isotopes labelled?

Answer 10

Isotopes are labelled according to their atomic number, and their mass number, and the chemical symbol of the element.

Question 11

What is a nuclide?

Answer 11

Each type of nucleus.

Question 12

What is the specific charge defined as?

Answer 12

The specific charge of a charged particle is defined as its charge divided by its mass.

Question 13

What is the proton numb er?

Answer 13

Also referred to as the atomic number, has the symbol Z, is the number of protons in the nucleus.

Question 14

How is the proton number significant?

Answer 14

The proton number defines the element, no two elements have the same number of protons.

Question 15

How can the proton number be used to obtain information about an atom’s chemical properties?

Answer 15

• In a neutral atom, the number of electrons equals the number of protons.
• The element’s reactions and chemical behaviour depend on the number of electrons.
• Therefore the proton number can tell you a lot about the chemical properties.

Question 16

What is the nucleon number?

Answer 16

• The Also known as the mass number, has the symbol A.
• Tells you how many protons and neutrons are in the nucleus.
Since each proton and neutron have a mass of 1, and the electrons have a mass of near to nothing, the number of nucleons is the same as the atom’s relative mass.