Section 10 - Key Concepts in Chemistry

Question 1

Chemical Equations, Risks and Hazards - What are the chemicals on the left hand side of a chemical equation called?

Answer 1

Reactants

Question 2

Chemical Equations, Risks and Hazards - What are the four state symbols?

Answer 2

Aqueous Solution (aq)
Solid (s)
Liquid (l)
Gas (g)

Question 3

Atoms, Isotopes and Electric Configurations - Describe the main features of the plum pudding model of the atom

Answer 3

• Atoms contain electrons

- Electrons are embedded in a sea of positive charge

Question 4

Atoms, Isotopes and Electronic Configuration - Name the three subatomic particles and state the relative charge of each

Answer 4

Proton = +1 charge
Neutron = 0 charge
Electron = -1 charge

Question 5

Atoms, Isotopes and Electronic Configuration - What does the mass number tell you about an atom?

Answer 5

The mass number tells us the number of protons AND neutrons in the nucleus of an atom

Question 6

Atoms, Isotopes and Electronic Configuration - What are isotopes?

Answer 6

Isotopes = different forms of the same element, which have the SAME number of PROTONS and a DIFFERENT number of NEUTRONS

Question 7

Atoms, Isotopes and Electronic Configuration - What can you say about the number of electron shells in elements in the same period?

Answer 7

Each new period represents another full electron shell. The period to which the element belongs corresponds to the number of shells of electrons it has

Question 8

Atoms, Isotopes and Electronic Configuration - What does the group number of an element in the periodic table tell you about its electronic structure?

Answer 8

The group number of an element tells you the number of electrons in the outermost shell

Question 9

Atoms, Isotopes and Electronic Configuration - How many electrons can fit into each of the first three electron shells?

Answer 9

2 in the first
8 in the second
8 in the third