Atomic structure

Question 1

Describe the structure of an atom

Answer 1

Atoms are made up of a nucleus (which contains protons and neutrons), with electrons orbiting around shells.

Question 2

What is the relative mass and relative charge of a proton, neutron and electron?

Answer 2

Proton : Charge - +1, Mass - 1
Neutron: Charge - 0, Mass - 1
Electron: Charge - -1, Mass - 1/1840

Question 3

Explain the terms atomic number, mass number, isotopes and relative atomic mass (Ar)

Answer 3

Atomic Number - The total number of protons in an atom.

Mass Number - The total number of sub-atomic particles inside the nucleus.

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

Relative Atomic Mass (Ar) - This is the combined relative masses of the nucleons in one particular isotope or an average of several isotopes.

Question 4

How do you the relative atomic mass of an element from the relative abundances of its isotopes?

Answer 4

Abundance x Atomic weight + Abundance x Atomic weight / 100

Question 5

What is the periodic table?

Answer 5

The Periodic Table is an arrangement of elements in order of atomic number

Question 6

How do you find out the electronic configurations of the first 20 elements from their positions in the Periodic Table?

Answer 6

Atomic number = no. of protons. No. of protons = no. of electrons, configuration = 2,8,8 etc. So fill in the number of electrons in the configuration.

Question 7

What is the relationship between the number of outer electrons and group number?

Answer 7

The group number of the element represents the number of electrons on the elements outer most shell. The periods represent the number of shells/orbitals the element has.