Answer:
At earlier times elements were arrangrd on the basis of their atomic masses to study their properties easily but there were various problems like isotopes needs different position in perodic table.
After discovery of atomic number modern periodic table was created on the basis of atomic number (number of proton) that is unique for each element and varies regularly. So study of a group of elements is much easier than each element seperately that is why modern periodic table was formed.
Explanation:
This is thermodynamics. When you increase the temperature of an object, the particles gain on kinethic energy ergo the move faster. When you decrease it, they slow down.
Answer:
Na3PO4 is excess reactant, CaCl2 is limiting reactant.
Explanation:
3CaCl2 + 2Na3PO4 ---> Ca3(PO4)2 + 6NaCl
from reaction : 3 mol 2 mol
given: 6 mol 5 mol (X)
X = (6*2)/3 = 4 mol Na3PO4
For 6 mol CaCl2 we need 4 mol Na3PO4, but we have 5 mol Na3PO4,
Na3PO4 is excess reactant, so CaCl2 is limiting reactant.
Answer:
mass ratio of A/B is 2:1
Explanation:
Since the mass of box A = 10g
mass of box B = 5g
Mass of box C = mass of box A + mass of box
A ratio compares two quantities. To find the ratio of the two boxes:
Ratio of A to B = 
Ratio of A to B = 
= 2
The mass ratio is 2:1 i.e box A has twice the mass of B
