atoms and molecules

Question 1

what are atoms?

Answer 1

it is the simplest unit of an element

Question 2

what are the three subatomic particles in an atom?

Answer 2

proton
neutron
electron

Question 3

structure of an atom

Answer 3

the atom is mostly made up of empty space. the electrons move around the nucleus (which is made up of protons and neutrons) at high speeds

Question 4

charges of subatomic particles

Answer 4

proton: +1
neutron: 0
electron: -1

Question 5

relative mass of subatomic particles

Answer 5

proton: 1
neutron: 1
electron 1/1840

Question 6

who made the billiard model? +describe the model

Answer 6

john dalton. he joined wooden balls with holes by using hooks to show how atoms could be combined

Question 7

who made the plum pudding model? +describe the model

Answer 7

j. j. thompson. the electrons (plums) were found within the mass of protons (pudding).

Question 8

what are molecules made of?

Answer 8

molecules are made of two or more atoms (of the same/different element) that are chemically combined.

Question 9

definition of a molecule of an element

Answer 9

consists of only one type of atoms that are chemically combined e.g. N2 (nitrogen), O2 (oxygen)

Question 10

definition of molecule of an compound

Answer 10

consists of two or more different types of atoms that are chemically combined

Question 11

what are knowledge of atoms used for?

Answer 11

• provide nuclear energy
• applied in radiation therapy to cure diseases
• medical imaging

Question 12

disadvantages / consequences of nuclear energy

Answer 12

accidents at nuclear power plants can result in the loss of lives and environmental pollution. the use of atomic bombs can bring about destructive effects