Given :
Number of He atoms,
atoms.
To Find :
How many grams are their in given number of He atoms.
Solution :
We know, molecular mass of He is 4 g. It means that their are
atoms in 4 g of He.
Let, number of gram He in
atoms is x , so :

Therefore, grams of He atoms is 22.58 g .
What science , what grade ?
Answer:
the original concentration of A = 0.0817092 M
Explanation:
A reaction is considered to be of first order it it strictly obeys the graphical equation method.

where;
k = the specific rate coefficient = 3.4 × 10⁻⁴ s⁻¹
t = time = 5.0 h = 5.0 × 3600 = 18000 seconds
a = initial concentration = ???
a - x = remaining concentration of initial concentration at time t = 0.00018 mol L⁻¹







a = 0.0817092 M
Thus , the original concentration of A = 0.0817092 M