Science exam unit 2

Question 1

What is the name of this symbol and what hazards are associated with it?

Answer 1

Oxidizing agent, can cause fires

Question 2

Give an example of a mechanical mixture,Solution,Element,and a compound

Answer 2

Mechanical, Chocolate chips
Solution, Flat soda
Element, Gold
Compound, Carbon dioxide

Question 3

What are indicators of chemical and physical changes?

Answer 3

Physical, can be reverted back

Chemical, cant be reverted back

Question 4

What is the density of a liquid that has a mass of 5.5g and takes a volume of 11.0.mL

Answer 4

V/M
M/D
DxV

Question 5

(grab a sheet of paper) Draw the bohr-Rutherfords diagram for Mg, Chlorine, and neon.

Answer 5

1, 2
2, 8
3, 18
4, 32
5, 50
6, 72

Question 6

What is the same about the valence electrons of all halogen elements? How does this explain why they are likely to react and form compounds with alkali metals?

Answer 6

They’re very reactive as they only need 1 electron to complete their outer shell

Alkali metals have 1 electron in their outer shell

Question 7

Give an example of an element in each of these groups, Metals, non metals, metalloids, Halogens, noble gases, alkaline earth metals, alkali metals.

Answer 7

Metals, Lithium
Non metals, Hydrogen
Metalloids, Boron
Halogens, F
noble gasses, Flourine
alkaline earth metals, Berilyum
Alkalkali metals, lithium

Question 8

Describe the difference between an ionic and covalent molecular compound

Question 9

What type of bond is formed in the following compounds (ionic or molecular. Nal CH4, ZnO

Answer 9

Ionic has metal

Nal, Ionic
Ch4, molecular
Zn0, Ionic

Question 10

What’s the difference between the two isotopes of carbon: carbon-14 and carbon-12?

Answer 10

Carbon has 14 has two more neutron

Question 11

What are the 3 main sub-atomic particles? What are the charges of the particles?

Answer 11

Proton +, electron -, neutron =