The molecular mass is 44.01 g/mol
Answer : The formula unit of Sr & Cl is 
and the formula unit of Al & S is 
Explanation :
Formula unit : it is defined as the lowest number ratio of ions of an elements in an ionic compound or covalent compound.
For the formula unit of Sr & Cl, two chloride ions
are needed to neutralize the one strontium ion
.
For the formula unit of Al & S, three sulfide ions
are needed to neutralize the two aluminium ion
.
The formula unit of and are shown below.
The characteristic bright-line spectrum of an element is produced when its electrons return to lower energy levels To be in the ground state all electrons must be in their lowest energy state; all excited atoms must lose energy. The lost energy appears in the form of light. Hope this helped :)
42metres / 6metres which means it takes 7 seconds to run 42 metres
