<u>Answer:</u>
The correct answer option is a. Selenium (Se).
<u>Explanation:</u>
From the given answer options, Selenium (Se) is the only element which is a non metal.
It has the atomic number 34 with atomic weight 78.96. It is a member of the sulfur group of the non metallic elements and falls in period 4 of the Periodic table.
Selenium has non metallic properties which are intermediate between the elements that lie above and below it in the Periodic table.
The answer is false. The correct answer would be efficiency.
The positively charged particle of an atom is called Proton.
The negatively charged particle of an atom is called an electron.
B I’m pretty sure. (Sorry if I wrong-)
Answers are Intermolecular and London dispersion
