Answer : The mole ratios of Hydrazine to Hydrogen peroxide is 1 : 2 and
the mole ratios of Hydrazine to water is 1 : 4.
Explanation :
The balanced chemical equation is,

According to the given reaction,
1 mole of Hydrazine react with the 2 moles of Hydrogen peroxide.
Therefore, the mole ratios of Hydrazine to Hydrogen peroxide is 1 : 2
And in case of Hydrazine and water,
1 mole of Hydrazine gives 4 moles of water.
Therefore, the mole ratios of Hydrazine to water is 1 : 4
Answer:
atomic number of Be =4
electronic configuration :1s²2s²
but for Be2+ atomic number = 4-2 =2
electronic configuration : 1s²
Mg(NO3)2 => <span>Magnesium nitrate
hope this helps!</span>
Answer:
A is denser than B as it's volume for the same mass is smaller.
Explanation:
Hello.
In this case, we first need to take into account that the density of each metal A and B is computed by dividing the mass over the volume of each metal which is actually computed by substracting the volume of water from the volume of the water and the solid:

Next, we compute the densities as shown below:

In such a way, A is denser is B as it's volume for the same mass is smaller.
Best regards.