Answer:

Explanation:
1. Calculate the adult life
If the elephant is an adult from its 10th birthday until the day before its 56th birthday, its
Adult life = 55 - 10 + 1 = 46 yr
2. Convert years to days

3. Convert days to pounds of feed

4. Convert pounds to kilograms and megagrams

Note: The answer can have only two significant figures because that is all you gave for age of the elephant.
Answer:
We will expect 4 moles of MgO to be formed (option b).
Explanation:
Step 1: The balanced equation
2Mg + O2 → 2MgO
Step 2: Data given
Number of moles of Magnesium = 4 moles
Oxygen = in excess → this means Magnesium is the limiting reactant
Magnesium will completely be consumed ( 4 moles). There will remain 0 moles.
For 2 moles of magnesium consumed, we need 1 mole of oxygen to produce 2 moles of MgO.
For 4 moles of magnesium, we need 4/2 = 2 moles of oxygen.
For 4 moles of magnesium, we will produce 4/1 = 4 moles of MgO
We will expect 4 moles of MgO to be formed (option b).
D. Electrons orbit in a fixed shell
Covalent compounds: N2, CCl4, SiO2 and AlCl3.
Ionic compounds: CaCl2 and LiBr.
Hope this helps!