<u>a) Answer: </u>
<em>Number of molecules in 1 mole</em>
<u>Explanation:</u>
a) Whether we take any of the substance among all three of the given substances they will have the same number of molecules in 1 mole of the substance is considered and the value for this will be 
<u>b) Answer: </u>
<em>In the given question </em><em>mass of the substance</em><em> which is </em><em>greatest</em><em> is asked for </em><em>one mole</em><em> and we also know that </em><em>mass of one mole is given by molar mass. </em>
<u>Explanation:</u>
b) It is known that 
is the molar mass for oxygen which is greater than that of hydrogen while fluorine has a molar mass of 
which on comparison shows that, it is the highest amongst all three.
1 calorie is equal to 4.184 Joules.
The question is confusing and all the answers are not there but it is B C and D
The partial pressure of the N2H4 gas is 1.50 atm.
<h3>Dalton's law of partial pressure</h3>
From the Dalton's law of partial pressure, the total pressure of a mixture of gases is the sum of the individual partial pressures of all the gases present in the mixture.
We have the following;
C2H2F4 = 3.00 atm
N2H4 = c
Total pressure = 3.00 atm + 1.50 atm = 4.50 atm
Hence, the partial pressure of the N2H4 is N2H4.
Learn more about partial pressure: brainly.com/question/14623719
Answer:
Sodium and Magnesium
Explanation:
The elements in Groups 1 and 2 get more reactive as you go down the group.
This means that Sodium is more reactive than lithium and Magnesium is more reactive than beryllium.
On the periodic table, as you go down the group, the reactivity of an element increases. Especially with metals in group 1 and 2. Now Lithium is a metal of group 1, followed by Sodium, while Beryllium is a metal in group 2, followed by magnesium. That's how I picked the answers
