The traditional calcium atom has twenty protons and twenty electrons making it neutral.
The calcium in the pic is a calcium ion so the number of protons and electrons are not equivalent.
Since it's 2+ that means the ion is positively charged and for that to happen electrons are away.
So 20-2=18
There are 18 electrons
In a simple distillation setup, the sequence of equipment from the bench top to the round bottom flask is:
- Thermometer
- Distillation flask
- Round bottom flask
- Bunsen burner
<h3>What is Distillation?</h3>
This is the process in which a mixture is separated through selective boiling and condensation.
The distillation flask and liebig condenser are usually located above the round bottom flask in the set up.
Read more about Distillation here brainly.com/question/24553469
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I believe the answer is A.
Hope this helps! ^^
Answer:
a. The student performed the splint test incorrectly. He should of observed a popping sound when the splint was placed in the test tube.
Explanation:
It is given that a student performed an experiment where he dropped a nickel metal in to HCl solution. He observed the reaction and performed a splint test in the test tube that is filled with a gas which is formed while Nickle is dropped into the solution of HCl.
But the experiment that the student performed was incorrect. He must have observed the popping sound when the splint was placed in the test tube.
When the splint was added to the gas splint flared up. The hydrogen gas pops out when exposed to the flame.

Thus the correct option is (a).
Cu⇒ 1 atom
N⇒2 atoms
O⇒6 atoms
Total 9 atoms
<h3>Further explanation </h3>
The empirical formula is the smallest comparison of atoms of compound forming elements.
A molecular formula is a formula that shows the number of atomic elements that make up a compound.
<em>(empirical formula) n = molecular formula </em>
Chemical formula : Cu(NO₃)₂
Number of Cu : 1
Number of N : 2
Number of O = 2 x 3 = 6
Total atoms in Cu(NO₃)₂ : 1 + 2 + 6 = 9