Answer: Option b. 50 neutrons and 38 protons.
Explanation:
Atomic number = proton number = 38
Mass number = proton number + Neutron
Mass number = 88
Proton = 38
Neutron number =?
Neutron number = Mass number — proton number
Neutron number = 88 —38 = 50
For Anyone that put A, its wrong, the correct answer is D
Na is the symbol for sodium.
Answer : It takes time to produce 3 g of aluminium is, 165 seconds.
Explanation :
As we are given that the mass of aluminium is, 3 grams. Now we have to calculate the total mass of aluminum.
Total mass of aluminum = 3g × 24 = 72 g
Now we have to calculate the moles of aluminum.

Molar mass of Al = 27 g/mol

As, 1 mole of Al has 3 Faradays
So, 2.67 mole of Al has =
Faradays
and,
Charge = 
Current = 
Now we have to calculate the time.

Hence, it takes time to produce 3 g of aluminium is, 165 seconds.
B.) Instantaneous speed because the speedometer shows how fast you are going at that giving time .