a) The E might belong to group 13.
As the formula of a chemical compound is derived by the cross multiplication of the valency of the atoms. As formula of the given oxide is and valency of O atom is -2, therefore valency of element E must be +3 in order to obtain E2O3.
Also, in EF3, the valency of E will be +3 because there are three atoms of fluorine who has an individual valency of -1. Thus, e will have the valency of +3.
The Group 13 is the boron group which has the following elements:
- Boron
- Aluminium
- Gallium
- Indium
- Thallium
All these elements have the valency of +3.
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Answer:
55
Explanation:
if you sub and I am writing it simple
If one half-life is 5,730 years, so four half-lifes is: 5,730 × 4 = 22,920
The approximate age of the fossil is 22,000 years
Answer : Note : The formula give in the question needs to be corrected , the formula of two chlorine atoms for every magnesium atom in the compound is which is Magnesium Chloride.
Explanation : To write the formula of the compound we need to know the charge of the atoms or elements involved in the formula.
Charge of Mg is +2 and charge of Cl is -1 , to write the formula of the compound we always criss cross the charges. And also when we write the formula the total (or net) charge of the compound should be 0. Charge of Mg is +2 so to get the total(net) charge as 0 we need two Cl atoms with each -1 charge.
Mg = +2 , Cl = -1 , Cl = -1
2 Cl = -1 + (-1) = -2
Mg = +2 and 2 Cl = -2
+2 -2 = 0
So the formula for Magnesium Chloride is