Scientist and Chemical Engineers
QUESTION:- Which particle has a mass of 9.11 x 10^-28g and charge of -1?
OPTIONS:-
A. electron
B. proton
C. neutron
ANSWER:-
CHARGE ON PROTRON IS +1 AND IT HAS MASS OF 
SO IT CANNOT BE URE ANSWER
THERE IS NO CHARGE ON NEUTRON AND HAS MASS ALMOST EQUAL TO THE PROTON SO IT ALSO CANNOT BE URE ANSWER
MASS OF THE ELECTRON:- 
CHARGE ON ELECTRON:- 
SO URE ANSWER IS ELECTRON
Answer:
b it increases from left to right of the group and it decreases down the period.
Answer:
33.7 kg
Explanation:
Let's consider calcium phosphate Ca₃(PO₄)₂.
The molar mass of Ca₃(PO₄)₂ is 310.18 g/mol and the molar mass of P is 30.97 g/mol. In 1 mole of Ca₃(PO₄)₂ (310.18 g) there are 2 × 30.97 g = 61.94 g of P. The mass of Ca₃(PO₄)₂ that contains 3.57 kg (3.57 × 10³ g) of P is:
3.57 × 10³ g × (310.18 g Ca₃(PO₄)₂/61.94 g P) = 1.79 × 10⁴ g Ca₃(PO₄)₂
A particular ore contains 53.1% calcium phosphate. The mass of the ore that contains 1.79 × 10⁴ g of Ca₃(PO₄)₂ is:
1.79 × 10⁴ g Ca₃(PO₄)₂ × (100 g Ore/ 53.1 g Ca₃(PO₄)₂) = 3.37 × 10⁴ g Ore = 33.7 kg Ore
