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 
Answer:
E
C
B
D
A
Explanation:
The definition of words correspond well with the answers I provided and somewhat match with the dictionary definitions.
I’m pretty sure it’s D.increases the activation energy for a reaction.
-Positively charged nucleus
-Empty spaced
-Dense core
The number of chlorine atoms present on the product side of the reaction is 6
<h3>What is a chemical equation? </h3>
Chemical equations are representations of chemical reactions using symbols and formula of the reactants and products.
The balancing of chemical equations follows the law of conservation of matter which states that matter can neither be created nor destroyed during a chemical reaction but can be transferred from one form to another.
<h3>How to determine the number of atoms of Cl</h3>
2Al + 6HCl → 2AlCl₃ + 3H₂
Products => AlCl₃ and H₂
Number of Cl atoms = 2 × 3
Number of Cl atoms = 6 atoms
Learn more about chemical equation:
brainly.com/question/7181548
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