Answer: correct option will D.
Explanation:
Calcium belongs to the group 2 i.e. of alkaline earth metals in periodic table. electronic configuration of calcium is
.
So in order to attain noble gas configuration calcium will loose its two electrons during chemical bond formation.

Sulfur is a non metal which forms negatively charged ion so as to complete ts octet during chemical bond formation.
Helium is a noble gas with fully filled electronic configuration.
Carbon forms bond which is covalent in nature.
Answer:
An element is a pure substance that cannot be converted further into anything simpler than itself by physical or chemical process
climate change and it could make it harder for us as humans and animals to breath move or doing everyday tasks
Answer:
acid base reaction this is answer