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.
To know more about Valency, refer to this link:
brainly.com/question/12717954
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It is potassium 39 definately
Significant figures are numbers that are not 0s, but they are included if they are between two numbers:
There are three significant figures, 304
Hope this helps! :)
The answer is 0.492 because there are 100 meters in a hectometer, and 49.2/100 is 0.492
