Answer: 
Explanation:
A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.
A double displacement reaction in which one of the product is formed as a solid is called as precipitation reaction.
The balanced chemical equation is:

Fossils are important evidence for evolution because they show that life on earth was once different from life found on earth today
Answer:
3rd option. 1–butanamine
Explanation:
To name the compound above, the following must be observed:
1. Locate the functional group in the chain. In this case the functional group is amine.
2. Locate the longest continuous carbon chain. This gives the parent name of the compound. In this case, the longest chain has 4 carbon i.e butane.
3. Since the functional group is amine, the parent name becomes butanamine i.e replacing the –e at the end in butane with –amine
4. Indicate the position of the functional group in the chain. In this case the functional group is at carbon 1
5. Name the compound by putting the above together.
The name of the compound is:
1–butanamine or butan–1–amine
The formula equation for the reaction between sulfuric acid and dissolved sodium hydroxide will be the same even if all products and reactants are in the aqueous or in the <span>liquid phase. It is as follows:
</span><span>
H2SO4 + 2NaOH = Na2SO4 + 2H2O</span>
patterns are important because they prove life has meaning ( or if you mean
Scientifically is is that the ability to recognize and create patterns help scientists make predictions based on there observations.