B and D is out. It cant be A because heat of combustion is substance not compound. So the answer is D.
<u>Answer:</u> The true statement is iron can reduce 
to gold metal
<u>Explanation:</u>
Single displacement reaction is defined as the reaction in which more reactive element displaces a less reactive element from its chemical reaction.
The reactivity of metal is determined by a series known as reactivity series. The metals lying above in the series are more reactive than the metals which lie below in the series.
Metal A is more reactive than metal B.
We are given:
Iron can reduce copper, silver can reduce gold, sodium can reduce iron and copper can reduce silver metal.
The increasing order of reactivity thus follows:
where, sodium is most reactive and gold is least reactive
For the given options:
<u>Option 1:</u> Copper cannot easily reduce sodium ion to sodium metal because it is less reactive.
<u>Option 2:</u> Iron cant easily reduce gold ion to gold metal because it is more reactive.
<u>Option 3:</u> Silver cannot easily reduce iron ion to iron metal because it is less reactive.
Hence, the true statement is iron can reduce to gold metal
From the calculation, the moles of water produced is 18 moles of water.
<h3>What is a decomposition reaction?</h3>
A decomposition reaction is one in which a substance is split up into smaller parts.
We have the reaction; 2 Cr(OH)3(aq) ------------> Cr2O3(s) + 3H2O(l)
From this reaction;
2 moles of Cr(OH)3 produced 3 moles of water
12 moles of Cr(OH)3 will produce;
12 moles * 3 moles / 2moles
= 18 moles of water
Hence, 12 moles of chromium (III) hydroxide produces 18 moles of water.
Learn more about decomposition reaction:brainly.com/question/8009068?
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Answer: it honestly depends.
Explanation:
Answer:
A. The children will be more likely to survive than if they did not have the trait.
Explanation:
Process of elimination
B. It will not affect the children.
Cannot be true, if it didn't impact the children then how would survival of the fittest work?
D. The children will be able to adapt if the environment changes.
That just... not how adapting works when it comes to evolution.
C. The children will be more likely to survive than their parents were
Everyone has the same trait, everyone is equal in that regard.
A. The children will be more likely to survive than if they did not have the trait.
"Suppose a pair of animals has a trait that helps them survive in their environment." The trait helps them survive. Not having the trait makes them less likely to survive. A is correct
