Answer:

Explanation:
Total spectators = 5000
Counted by the groups of ten, So at last the result will be:
=> 5000/10 = 500
Significant figures in 500 are 3
Answer:
CuCl2 + H2S -> CuS + 2HCl
Explanation:
in the reactants the 2 in 2HCl multiplies to give you 2 Hydrogens and 2 Chlorides.
The letter i is used to signify that a number is an imaginary number. It stand for the square root of negative one.
You first subtract the speed at which the man is moving (11 m/s) from the rate the boat is moving (12.4 m/s). Which equals 1.4, then divide it by 6 meters, as the man is moving relative to the boat.
It therefore equals 4.29 s
a heater that produces lots of warm air which would include thermal energy or a kitchen stove