Atomic Structures

Question 1

atom

Answer 1

Smallest part of an element

Question 2

molecule

Answer 2

A group of 2 or more atoms chemically bonded together

Question 3

atom structure

Answer 3

• consists of central nucleus composed of protons and neutrons
• nucleus surrounded by electrons orbiting in shells
• atoms are neutral because number of protons and electrons is equal

Question 4

relative masses

Answer 4

proton = 1
neutron = 1
electron = negligible

Question 5

relative charges

Answer 5

proton = +1
neutron = 0
electron = -1

Question 6

atomic number

Answer 6

number of protons in an atom
(smaller number)

Question 7

mass number

Answer 7

number of protons and neutrons in an atom.
(bigger number)

Question 8

isotopes

Answer 8

atoms of the same element with the same number of protons but a different number of neutrons

Question 9

relative atomic mass (Ar)

Answer 9

Average mass of all the isotopes of the element, relative to the mass of 1/12th of a carbon - 12 atom.

Question 10

calculate Ar

Answer 10

(mass x abundance) + (mass x abundance)
___________________________________________________
total number of atoms