Answer: (3)
Medeleev arranged elements in order of increasing atomic weight and similar properties
He noticed that similar elements were grouped together by using this.
Answer: -
0.1 ml of bleach should be added to each liter of test solution.
Explanation:-
Let the volume of bleach to be added is B ml.
Density of stock solution = 1.0 g/ml
Mass of stock solution = Volume of stock x density of stock
= B ml x 1.0 g/ml
= B g
Amount of NaOCl in this stock solution = 5% of B g
=
x B g
= 0.05 B g
Now each test solution must be added 5 mg/l NaOCl.
Thus each liter of test solution must have 5 mg.
Thus 0.05 B g = 5 mg
= 0.005 g
B = 
= 0.1
Thus 0.1 ml of bleach should be added to each liter of test solution.
Answer:
Explanation:
If an atom has 13 electrons then it belongs to p-block of periodic table.
s level can accommodate 2 electrons.
p level can accommodate 6 electrons.
13 means 1s2 2s2 2p6 3s2 3p1.
As you can see there totally 5 sub-shells.
Total number of shells are 3(1,2,3).
Explanation:
option A skeleton system is correct option
hope this helps you !