Helium is stable compound. exists in gaseous state. the answer is gas
Answer:
Element
Explanation:
A chemical element is a substance that contains only one type of atom, which is the smallest particle of an element
V= d/t
v=speed
d=distance
t=time
So v= 422/3
v =140.667m/s
Answer: C2H4 + 3O2 → 2CO2 + 2H2O
Explanation:
2Al + 2O2 → 2AlO + O2 Not Balanced Properly: 2Al + O2 = 2AlO
C2H4 + 3O2 → 2CO2 + 2H2O Looks Good
2CH4 + O2 → 2CO + 4H2 Not Correct: CO should be CO2
Ca + O2 → CaOH Not Balanced and No source for the H