The correct option is 2.
For a chemical equation to be balanced, the number of atoms of each element present in the reactants must be the same with that present in the products. If the number of atom of any element at any of the two side of the reaction is not the same, then the equation is not balanced. Looking at the options given above, it will be noticed that for option 2, the number of Sr atom at the reactant side is 1 while at the product side it is 2. This shows that the equation is not balanced.
Hey there!:
Molar mass CO2 = 44.01 g/mol
44.01 g CO2 ------------------- 6.02*10²² molecules CO2
88 g CO2 ------------------------ y
y = 88 * ( 6.02*10²² ) / 44.01
y = 5.29*10²⁵ / 44.01
y = 1.2 * 10²⁴ molecules of CO2
Answer A
Hope that helps!
While staying in the same period, if we move from left to right across the period, the atomic radius decreases. The reason is, in a period the number of shells remain the same and the number of electrons and protons increase as we move across the period to the right. The increased electrons and protons attract each other with greater force and hence the atomic size decreases.
So the element on the left most will have the largest atomic radius. So the correct ans is Potassium. Potassium will have the largest atomic size among Potassium, Calcium and Scandium.
