Explanation:
Atomic size is defined as the distance between the nucleus and valence shell of an atom. Valence shell is the outermost shell of an atom.
When we move across a period in a periodic table then there will occur a decrease in atomic size of the atoms. But when we move across a group in a periodic table then there will occur an increase in atomic size of the atom.
Hydrogen is a period 1 element, oxygen is a period 2 element, chlorine is a period 3 element and bromine is a period 4 element.
Therefore, given elements are arranged in order of increasing atomic size as follows.
H < O < Cl < Br
Answer:
Air is mostly gas
The air in Earth's atmosphere is made up of approximately 78 percent nitrogen and 21 percent oxygen. Air also has small amounts of lots of other gases, too, such as carbon dioxide, neon, and hydrogen.
Explanation:
plz mar k me brainlist
have a nice day
Answer:
I think it would be c I hope it this helps and it's right
Answer:
They increase the concentration of the reactants
Explanation:
