Answer: Burning changes the chemical make up of an object.
Explanation:
A chemical change can be defined as a change in the substance when it combines with other kind of substance to form a new substance. A chemical change can also occur when a substance is broken down into two or more products. These changes cannot be reversed. These changes affect the physical make up of an object. For example, burning as when an object is burned it cannot be transformed into its original form. A wood if burned can be converted into ash, water and carbon dioxide cannot regain its original form after burning so burning brings about chemical change in an object.
The percentage of yield was 777.78%
<u>Explanation:</u>
We have the equation,
Be
[s] + 2
HCl
[aq] → BeCl
2(aq] +
H
2(g] ↑ Be
(s] +
2
HCl
[aq] → BeCl
2(aq] +
H
2(g]
↑
To find the percent yield we have the formula
Percentage of Yield= what you actually get/ what you should theoretically get x 100
=3.5 g/0.45 g 100
= 777.78 %
The percentage of yield was 777.78%
Your answer would be 0.00285 moles.
1 mole ----------- 6.02 x 10²³ atoms
? mole ---------- 24.08 x 10²³ atoms
moles B = ( 24.08 x 10²³) x 1 / 6.02 x 10²³
moles B = 24.08 x 10²³ / 6.02 x 10²³
= 4 moles
Answer B
hope this helps!
