Answer:
(a):Valency is the measure of the capacity of an atom of a single element to react and combine with particular numbers of atoms of another element.
(b):
Valency of calcium:+2
Valency of Iron:Iron exhibits 2 valence states of +2 and +3.
Valency of hydroxl:-1
Valency of Nitrate:-1
Explanation:
Answer:
The metallic oxide is Li₂O
Explanation:
Let the metallic oxide be M₂O
Thus;
M₂O + H₂ = 2M + H₂O
Molar mass of M₂O = (2x + 16)
We assume Molar mass of M to be x.
We are told that 5.00 g of the metallic oxide produces 2.32 g of the metal.
By proportion, we can write the following;
5g of M₂O × (1 mole of M₂O/(2x + 16)) × (2 moles of M/1 mole of M₂O) = 2.32 g of M × 1 mole of M/x g of M
This cancels out to give us;
10/(2x + 16) = 2.32/x
Cross multiply to get;
10x = 2.32(2x + 16)
10x = 4.64x + 37.12
10x - 4.64x = 37.12
5.36x = 37.12
x = 37.12/5.36
x = 6.925 g/mol
The metal with a molar mass closest to this value of x is Lithium which has a molar mass of 6.94 g/mol
Thus the metal is Lithium and as such the metallic oxide is Li₂O
Answer:
The vertical columns are called groups.
Explanation:
Periodic table consist of vertical columns and horizontal rows.
Vertical columns are called groups while horizontal rows are called periods.
There are seven periods and 18 groups in periodic table.
The elements in same group have similar properties and can react in a similar way.
The elements in same group have same number of valance electrons that's why their reactivity is same.
Consider the example of alkaline earth metals. They are present in group two and have same number of valance electrons (two valance electrons).
They react with oxygen and form oxide.
2Ba + O₂ → 2BaO
2Mg + O₂ → 2MgO
2Ca + O₂ → 2CaO
this oxide form hydroxide when react with water,
BaO + H₂O → Ba(OH)₂
MgO + H₂O → Mg(OH)₂
CaO + H₂O → Ca(OH)₂
With sulfur,
Mg + S → MgS
Ca + S → CaS
Ba + S → BaS
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