Answer : The number placed in front of 
should be, three (3).
Explanation :
Balanced chemical reaction : It is defined as the number of atoms of individual elements present on reactant side must be equal to the product side.
The given unbalanced chemical reaction is,
This chemical reaction is an unbalanced reaction because in this reaction, the number of atoms of chloride and sulfate ion are not balanced.
In order to balanced the chemical reaction, the coefficient 3 is put before the , the coefficient 2 is put before the 
and the coefficient 3 is put before the 
.
Thus, the balanced chemical reaction will be,
Therefore, the number placed in front of should be, three (3).
Explanation:
Given elements:
F, Sr, P, Ca, O, Br, Rb, Sb, Li, S
Elements with the same chemical reactivity will belong to the same group on the periodic table. This implies that elements in the same column will have the same reactivity;
Li and Rb are both alkali metals in group 1
Ca and Sr are both alkali earth metals in group 2
F and Br are halogens in group 7
O and S are group 6 elements
P and Sb are both in group 5 on the periodic table
So these groupings show elements with the same chemical properties.
Answer:
4.00 moles
Explanation:
Avogadro´s number is 6.022 x 10²³ molecules, atoms, particles, etc.
Here we are talking of atoms of copper, so 1 mol of copper is equal to 6.022 x 10²³ atoms, and we only need to setup the proportion to find the number of mol in 2.41 x 10²⁴ atoms. ( Think of it like a dozen, avogadro´s is 6.022 x 10²³ )
( 1 mol copper/ 6.022 x 10²³ atoms of copper ) x 2.41 x 10²⁴ atoms
= 4.00 moles
