The atom

Question 1

What was John daltons version of the Atom?

Answer 1

A solid sphere that could not be divided into small parts. No electrons, protons or neutrons.

Question 2

What was the Plum pudding model of the atom?

Answer 2

Experiments led to the discovery of sub-atomic charged particles. First, elecrons. The theory was that there was a large cloud of positive charge with electrons dotted around.

Question 3

What was the Alpha scattering experiment?

Answer 3

1. Scientists fired small positively charged particles at a gold sheet only a few atoms thick.
2. They expected the alpha particles to go through the gold.
3. They found the alpha particles bounced back.
4. This led to a theory of a postively charged nucleus with mass.

Question 4

What was the Nuclear model?

Answer 4

Scientists replaced the plum pudding model with the and suggested the electrons orbit the nucleus.

Question 5

What was the bohr model?

Answer 5

Niels bohr calculated that electrons must orbit the nucleus in shells or layers.

Question 6

What did James chadwick do for the discovery of the atom?

Answer 6

Carried out experiments that gave evidence for a particle with no charge.

Question 7

What is the size of an atom?

Answer 7

Radius = 1x10 to the -10

Question 8

What is an element?

Answer 8

Substances made up of one type of atom with each atom having the same number of protons.

Question 9

What is a compound?

Answer 9

Compounds are made up of different types of atoms chemically bonded together.

Question 10

What is a mixture?

Answer 10

• A mixture consists of two or more compounds that are not chemically combined.
• The substances in a mixture can be seperated.

Question 11

What are the 5 ways of seperating a mixture?

Answer 11

• Filtration
• Crystallisation
• Simple distillation
• Paper chromatography in solution