Valence Electron is the outermost electrons, family(Alkali) 1 has 1 valence electrons and family(Alkaline) 2 has 2 valence electrons.
Hope this helps
Answer:
Question 6
Plants use flowers to absorb photsynthese
nuclear power--used to turn turbines...
fossil fuels--burned to provide energy that is....
renewable energy--energy that with come back after use
outlet--a device....
steam--nuclear reactors....
I'm not sure but I tried lol,lemme know if I'm wrong :D
Answer : The mass in grams of calcium sulfate is 0.16 grams.
Explanation :
Molarity : It is defined as the number of moles of solute present in one litre of solution.
Formula used :

Solute is, 
Given:
Molarity of
= 0.0025 mol/L
Molar mass of
= 136 g/mole
Volume of solution = 485 mL
Now put all the given values in the above formula, we get:


Thus, the mass in grams of calcium sulfate is 0.16 grams.
Explanation:
21. The given molecule for cracking is tetradecane.
On cracking it forms one mole of decane (C10H22) and two moles of ethene gas.
The chemical equation is shown below:

22. The essential condition for the formation of an ester is the reaction of alcohol and acid in presence of concentrated sulfuric acid.
Thus among the given options, the first option is the correct one.
23. Isomers of butanol are shown below:
It is 2-butanol.
The position of -OH group changes to the second carbon.