Answer:

Explanation:
Calcium is the element of the group 2 and period 4 which means that the valence electronic configuration is
.
Chlorine is the element of the group 17 and period 3 which means that the valence electronic configuration is
.
Thus, calcium losses 2 electrons to 2 atoms of chlorine and these 2 atoms of chlorine accepts each electron to form ionic bond. This is done in order that the octet of the atoms are complete and they become stable.
Ca Cl
2 1
Cross multiplying the valency, We get, 
Thus, the formula of calcium chloride is
.
Answer:
Al2(SO4)3
Explanation:
Looking at this carefully, we will discover that Al2(SO4)3 is composed of Al^3+ and SO4^2-.
The aluminum and sulphate ions are ionically bonded. However, the oxygen and sulphur in the sulphate ion are covalently bonded.
Hence, Al2(SO4)3 contains both ionic and covalent bond.
3.37 x 10¹⁰ molecules
Explanation:
Given parameters:
Volume of water = 1pL = 1 x 10⁻¹²L
Density of water = 1.00g/mL = 1000g/L
Unknown:
Number of water molecules = ?
Solution:
To solve this problem, we first find the mass of the water molecule in the inkjet.
Mass of water = density of water x volume of water
Then, the number of molecules can be determined using the expression below:
number of moles = 
Number of molecules = number of moles x 6.02 x 10²³
Solving:
Mass of water = 1 x 10⁻¹² x 1000 = 1 x 10⁻⁹g
Number of moles:
Molar mass of H₂O = 2 + 16 = 18g/mol
Number of moles =
= 5.6 x 10⁻¹⁴moles
Number of molecules = 5.6 x 10⁻¹⁴ x 6.02 x 10²³ = 33.7 x 10⁹
= 3.37 x 10¹⁰ molecules
Learn more:
Number of molecules brainly.com/question/4597791
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Because the sublevels 1s only has one shape ,and it only contains 2 elections...
Answer:
The further an electron is from the nucleus. the greater its energy level.
Explanation:
When an electron is close to the nucleus, it is at as low an energy level as it can get.
We must put energy into an electron to pull it away from the attraction of a nucleus.
So, electrons that are further from the nucleus are at higher energy levels.