ANSWER
72km/h
EXPLANATION
The average speed of the car can be calculated using the formula:
Average Speed=total distance/ total time taken.
The car covers a distance of 108km in 1½ hours.
We substitute the values into the formula to obtain,


Therefore the average speed of the journey is 72km/h
Answer:
See the attachment
Step-by-step explanation:
It is convenient to use a spreadsheet or graphing calculator for this.
Answer:
Barium, Strontium and Beryllium
Explanation:
There are 18 groups in the periodic table and the previous 3 all belong to the same group, group 2 the alkali metals
Silicon is group 14, the carbon group
Aluminum is in the boron group, group 13
Osminium is in the group 8 transition metals