it is b shared to form a covalent bond
Explanation:
A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between atoms, when they share electrons, is known as covalent bonding.
Number of atoms : 1.26 x 10²³
<h3>Further explanation </h3>
The mole is the number of particles(molecules, atoms, ions) contained in a substance
1 mol = 6.02.10²³ particles
Can be formulated
N=n x No
N = number of particles
n = mol
No = Avogadro's = 6.02.10²³
0.21 moles of Al, so n = 0.21
Number of atoms :

<h3><u>Answer;</u></h3>
A dense substance that is hard and incompressible
<h3><u>Explanation</u>;</h3>
- <em><u>Crystals are solids that are made up of particles such as molecules, atoms or ions, </u></em>which are arrange in a highly ordered microscopic structure, forming a crystal lattice which extends in all directions.
- Examples of crystals include<em><u> quartz,</u></em> that is made up of silicon (iV) oxide molecules that are arranged in a lattice,<u><em>table salt</em></u> is another example that is made up of sodium and chloride ions that are arranged in a lattice
- Crystals are very ordered, they may be made up of atoms of the same elements or atoms of different elements such as in the case of table salt.
I'm pretty sure it's called a volcanic winter, look up my answer to be correct though.
When an atom combines chemically with another atom, it either gains, loses, or shares ELECTRONS.