F4 Chapter 2: The Structure of an Atom

Question 1

According to the heating graph, why didn’t the temp change when being heated?

Answer 1

It is because the heat energy absorbed is used to overcome the forces of attraction between the particles

Question 2

According the cooling graph, why didn’t the temp decrease when bring cooled?

Answer 2

It is because the energy released is the same as the energy lost to the surrounding.
*Energy lost is to form bond between particles

Question 3

When heating a substance in a water bath, why must the level of substance be lower than water level? When cooling a substance, why must it be stirred continously?

Answer 3

To ensure uniform heating/cooling.

To prevent supercooling (Naphtalene)

Question 4

How did the atomic atom developed?

Answer 4

D.T.R.B.C

John Dalton: An empty atom
J.J Thompson: Electron & +ive charged sphere
Ernest Rutherford: Proton, nucleus and moving
electron
Neil Bohr: Shells, electrons orbiting around
James Chadwick: Neutrons & proton are found
in nucleus

Question 5

What is the standard presentation of atoms?

Answer 5

Nucleon Num
X
Proton Num

Question 6

What are the uses of

i. Cobalt-60
ii. Sodium-24
iii. Carbon-14
iv. Phosphorus-32
v. Iodine-131

Answer 6

i. For treatment of cancer
ii. Detect leakage in ground pipes
iii. Estimate age of artifacts and fossils
iv. Treat skin cancer
v. Treat thyroid disease

Question 7

What does an atom contain?

Answer 7

An atom contains protons, neutrons and electrons, where the electron has almost no weight