What does the group number of a elements in the a/b numbering system)
tell about valence electrons?

a. the a group number tells which period the valence electrons are
in
b. the a group number tells how much mass the elements have.
c. all elements in the same a group will have the same number of
valence electrons.
d. all elements in the a group will have the same valence electrons
as the b group.

All elements in the same A group will have the same number of

valence electrons.

Explanation:

Group A has 1 valence electrons.

plants need sunlight, water, and carbon dioxide to make food. plants use the raw materials of water, nutrients they absorb from soil, and carbon dioxide to make sugars the plant can use. energy from the sun and chlorophyll are also needed.

answer: the value of enthalpy change will be -152.80 kj.

solution:

pressure = 1atm , temperature = = 298 k

given that pressure and temperature are same in both gases , the number of moles of both gases can be determined by the ideal gas equation.

according to reaction 3 moles no are reacting with 1 mol of ,then 0.49 mol of no will react with moles of ozone that is 0.16 moles of ozone. since, no is limiting reagent and is an excessive reagent.

enthalpy change for the reaction between the given volumes of the gases is :