Calcium carbonate is CaCO3.
So there is calcium, symbol is Ca and an atomic number of 20.
Carbon: symbol is C and an atomic number of 6.
Oxygen: symbol is O and an atomic number of 8.
In one molecule of CaCO3, there is one atom of Ca, one atom of C, and three atoms of O as shown by the subscript next to O in the formula. There are no other subscripts to indicate more than one atom of the other elements, so there is only one atom of the other two elements
A quality I would say of a physical substance is hardness
ANSWER
The number of the unpaired electrons is 1
STEP-BY-STEP EXPLANATION:
The electronic configuration of a particular element is given below as

From the electronic configuration above, you will see that the 4s-orbital has two electrons and the 3d-orbital has 9 electrons
According to Hund's Rule, it "states that electron goes into orbital singly before pairing commences."
To determine the number of unpaired electrons, we need to study the total number of electrons in the d-orbital as given by the question.
Note that, the <em>maximum number of electrons</em> that can enter into the d-orbital is 10
The next step is to fill in the electrons into the orbital
From the above structure, you will see that the number of paired electrons is 4 and the number of unpaired electrons is 1
Therefore, the number of the unpaired electrons is 1
Answer:
Neon
Explanation:
Elements from group 8A stay alone
Answer:
A) bent
Explanation:
The water molecule has a bent molecular configuration because the lone electron pairs, although still exerting influence on the shape, are invisible when looking at molecular geometry.