<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.
Answer:
Erm.......... can you clarify what "paper", you just said "paper" there's a lot.
Explanation:
Answer:
d.
Explanation:
They can be spread through contaminated surfaces.
Answer:
b) Silicon and oxygen
Explanation:
A compound is a pure substance that contains two or more atoms chemically joined together. Sand is regarded as a 'compound' because it is made up of two or more atoms that are chemically bonded to one another.
Sand is said to predominantly contain silica, which has a chemical formula of SiO2. Hence, sand can be said to be a compound containing one atom of silicon (Si) and two atoms of oxygen (O2).
