Answer:
Explanation:
Given that:
The Half-life of 
= 
is less than that of 
Although we are not given any value about the present weight of .
So, consider the present weight in the percentage of to be y%
Then, the time elapsed to get the present weight of = 
Therefore;
here;
= Number of radioactive atoms relating to the weight of y of
Thus:
--- (1)
However, Suppose the time elapsed from the initial stage to arrive at the weight of the percentage of to be = 
Then:
---- (2)
here;
= Number of radioactive atoms of relating to 3.0 a/o weight
Now, equating equation (1) and (2) together, we have:
replacing the half-life of =
( since 
)
∴
The time elapsed signifies how long the isotopic abundance of 235U equal to 3.0 a/o
Thus, The time elapsed is
The answer should be c because the relationship of pressure and plus the temperature decrease in the center.
D. because matter is uniform through and cannot be separated into other substances by physical means.
answer: D
Here is a list of the most common ways to speed up a chemical reaction
Increase the temperature (reactions that absorb energy)
Decrease the temperature (Reactions that release energy)
Answer:
2.03125g of acetylene
Explanation:
First thing's first, we have to write out the balanced chemical equation;
CaC2(s) + 2H2O(l) → Ca(OH)2(aq) + C2H2(g)
Water is in excess, so CAC2 is our limiting reactant. i.e it determines the amount of product that would be formed.
1 mol of CaC2 produces 1 mol of C2H2
In terms of mass;
Mass = Number of moles * Molar mass
where the molar mass of the elements are;
Ca = 40g/mol
C = 12g/mol
H = 1g/mol
CaC2 = 40+ (2*12) = 64g/mol
C2H2 =( 2 * 12) + ( 2 * 1) = 26g/mol
64g (1 * 64g/mol) of CaC2 produces 26g ( 1mol * 26g/mol) of C2H2
5g would produce x?
64 = 26
5 = x
Upon solving for x we have;
x = (5 * 26) / 64
x = 2.03125g
