Explanation:
1. Explain how groups 1A-8A in the periodic table are organized by their number of valence electrons.
The valence electrons in an atom are the outermost shell electrons. They are the most loosely held electrons in an atom.
Coincidentally, the periodic table of elements divided into vertical groups and horizontal periods can be said to be arranged according to the number of valence electrons.
- Atomic numbers are used to arrange elements on the periodic table.
- Down a group, the number of electronic shell increases. More electrons are added to new energy levels.
- As we move from left to right across a period, the number of electrons in elements increases but electronic shell is the same.
- Down a group electronic shell increases but the number of valence electrons are the same.
- All elements in Group 1A has just one valence electrons, Group 2A has two valence electrons.........Group 8A has eight valence electrons.
- Moving across groups is synonymous to moving from left to right on the periodic table.
- Due to this trend, the periodic table is arranged based on the number of valence electrons.
3. explain how you know the number of valence electrons for each group.
The number of valence electrons in a group is the group number:
Group Number valence electrons
1A 1
2A 2
3A 3
4A 4
5A 5
6A 6
7A 7
8A 8
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Number of moles : n₂ = 1.775 moles
<h3>Further explanation</h3>
Given
Moles = n₁ = 1.4
Volume = V₁=22.4 L
V₂=28.4 L
Required
Moles-n₂
Solution
Avogadro's hypothesis, at the same temperature and pressure, the ratio of gas volume will be equal to the ratio of gas moles
The ratio of gas volume will be equal to the ratio of gas moles

Input the values :
n₂ = (V₂ x n₁)/V₁
n₂ = (28.4 x 1.4)/22.4
n₂ = 1.775 moles
Magma that cools quickly forms one kind of igneous rock, and magma that cools slowly forms another kind. When magma rise from deep within the earth and explodes out of a volcano, it is called lava, and it cools quickly on the surface. Rock formed in this way is called extrusive igneous rock.
Answer:
18.84 g of silver.
Explanation:
We'll begin by calculating the number atoms present in 5.59 g of sulphur. This can be obtained as follow:
From Avogadro's hypothesis,
1 mole of sulphur contains 6.02×10²³ atoms.
1 mole of sulphur = 32 g
Thus,
32 g of sulphur contains 6.02×10²³ atoms.
Therefore, 5.59 g of sulphur will contain = (5.59 × 6.02×10²³) / 32 = 1.05×10²³ atoms.
From the calculations made above, 5.59 g of sulphur contains 1.05×10²³ atoms.
Finally, we shall determine the mass of silver that contains 1.05×10²³ atoms.
This is illustrated below:
1 mole of silver = 6.02×10²³ atoms.
1 mole of silver = 108 g
108 g of silver contains 6.02×10²³ atoms.
Therefore, Xg of silver will contain 1.05×10²³ atoms i.e
Xg of silver = (108 × 1.05×10²³)/6.02×10²³
Xg of silver = 18.84 g
Thus, 18.84 g of silver contains the same number of atoms (i.e 1.05×10²³ atoms) as 5.59 g of sulfur
Answer: Rotation cause by the earths orbit and gravity
Explanation: