C). if 0.5 mole of oxygen (0,) reacted with hydrogen (h2), how many mole of water (h,0) was produced
from the reaction?

For 0.5 moles of oxygen consumed, there will be 1.0 moles of H2O produced.

Explanation:

Step 1: Data given

Number of moles of oxygen (O2) = 0.5 moles

Suppose  H2 is in excess

Step 2: The balanced equation

O2 + 2H2 → 2H2O

Step 3: Calculate moles of H2O

For 1 mol of O2 we need 2 moles of H2 to produce 2 moles of H2O

For 0.5 moles of O2 we'll have 2*0.5 moles = 1.0 moles of H2O

For 0.5 moles of oxygen consumed, there will be 1.0 moles of H2O produced.

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.