I think the answer is 1. HF
Explanation:
the investigation lasts for 7 days.
hope this helps you.
Answer:
20 molecules of oxygen gas remains after the reaction.
Explanation:

Molecules of ethyne = 52
Molecules of oxygen gas = 150
According to reaction, 2 molecules of ethyne reacts with 5 molecules of oxygen gas.
Then 52 molecules of ethyne will react with:
of oxygen gas.
As we can see that we have 150 molecules of oxygen gas, but 52 molecules of ethyne will react with 130 molecules of oxygen gas. So, this means that ethyne is a limiting reagent and oxygen gas is an excessive reagent.
Remaining molecules of recessive reagent = 150 - 130 = 20
20 molecules of oxygen gas remains after the reaction.
Answer:
4 atmospheric pressure is needed to get a volume of 25 litres
It’s either the first or second one
I think it’s the first one - the outer cells of the blastocyst