Ans is B.Bromine. Only two elements are liquid at room temperature ( mercury and Bromine) . Helium and chlorine, arsenic are gases.
Answer:
1250kg
Explanation:
Given parameters:
Acceleration = 1.2m/s²
Force = 1500N
Unknown:
Mass on the vehicle = ?
Solution:
According to newton's second law of motion:
Force = mass x acceleration
Since mass is the unknown, insert the parameters and solve;
1500 = mass x 1.2
mass = 
= 1250kg
Mass would be the amount of matter an object contains.
You have to use Avogadro's number which is 6.02x10^23. The units of Avogadro's number is molecules/mole so you divide the number of molecules by Avogadro's number which will give you the number of moles.
(2.0x10^22 molecules)/(6.02x10^23 molecules/mole)=0.033 moles
