Answer:
They all belong to the p block in the periodic table
Explanation:
Let us examine the electronic configuration of each element;
Oxygen - [He] 2s2 2p4
Silicon - [Ne] 3s2 3p2
Selenium - [Ar] 4s2 3d10 4p4
A common thread that joins all the elements listed above is that they all belong to the p-block in the periodic table. They could be collectively referred to as p-block elements.
Carbon normally bonded to Hydrogen, Nitrogen, Oxygen
Answer:
Infectious diseases are commonly transmitted through direct person-to-person contact.
The main four pathogens are virus, bacteria, protists and fungi.
Bacteria, fungi and protists can reproduce wherever the conditions are warm, with plenty of moisture, nutrients, and space. Viruses can only reproduce by invading living cells.