Answer:
Chlorine (Cl)
Explanation:
The equation would be:
→ 
This is because no atom is lost in a reaction. Chlorine would be the missing chemical as it is on the other side of the equation and needs to be accounted for on the products side.
Energy absorbed by Iron block E (iron) = 460.5 J
Energy absorbed by Copper block E (Copper) = 376.8 J
<u>Explanation:</u>
To find the heat absorbed, we can use the formula as,
q = m c ΔT
Here, Mass = m = 10 g = 0.01 kg
ΔT = change in temperature = 400 - 300 = 100 K = 100 - 273 = -173 °C
c = specific heat capacity
c for iron = 460.5 J/kg K
c for copper = 376.8 J/kg K
Plugin the values in the above equation, we will get,
q (iron) = 0.01 kg × 460.5 J/kg K × 100 K
= 460.5 J
q (copper) = 0.01 kg × 376.8 J/kg K × 100 K
= 376.8 J
Answer:
Yes
Explanation:
First remember that a significant figure are basically values that contribute to the precision of a value. In any scientific notation the values are significant figures because these values stay the same. In this case we have two significant figures which is 6 and 0, you can further prove that they are significant figures by converting the notation into standard form.

Negative so move the decimal point to the left:

6 and 0 are the significant figures in this standard notation because it's precise to it's actual value which is 6.0.
To sum up, the values you have on the left side of a notation are significant figures since they will not change no matter if it's standard or scientific notation meaning it's precise.
Hope this helps.
I think the b is right ( Saturated Alkyne)