C1.2 Flashcards
1
Q
What is bond length?
A
Bond length:
- Distance between centre of two joined atoms
2
Q
What is atomic number?
A
Atomic number:
- Number of protons
- Sam number of protons and electrons
3
Q
What is relative atomic mass?
A
Relative atomic mass:
- Number of protons + neutrons
4
Q
What is an isotope?
A
Isotope:
- Element with same amount of protons
- Different amount of neutrons
- Same atomic number
- Different mass number
5
Q
What are ions?
A
Ions:
- Charged particles
- Formed when atoms lose or gain electrons
6
Q
What did Dalton do?
A
Dalton:
- All atoms of element are identical
- Different elements contain different atoms
7
Q
What did Thomson do?
A
Thomson:
- Discovered electron
- Cathode rays were electrons
8
Q
What was the plum-pudding model?
A
Plum-pudding model:
- Atoms are spheres of positive charge with electrons dotted around it
9
Q
What did Rutherford do?
A
Rutherford:
- Tested plum-pudding model by firing alpha particles at thin piece of gold foil
- Expected all particles to go through
- Some deflected back (more than 90 degrees)
- Concluded that there is a positively charged nucleus that contains most of mass
10
Q
What did Bohr do?
A
Bohr:
- Electrons occupy fixed energy levels around nucleus
