Q1.Write down advantages and disadvantages of Mendeleev's Periodic table? Plz Help Me I Want To Make Notes For It

the advantage is that he discover many element unknown that time

And the disadvantage is wrong order of atomic masses and the position of isotopes

Explanation:

Disadvantage: the isotopes and no separate position also as they have different atomic mass but same atomic number. Since the change in atomic mass of two successive elements was not constant therefore it was difficult to predict the number of missing elements with the help of atomic number only.

It could predict the existence of other elements and could predict their properties so, as to leave space in the periodic table. It could accommodate all the sixty elements discovered at that time and could accommodate the noble gases which, where discovered later.

(newtons first law)

conservation of momentum law states :

momentum before collision = momentum after collision

momentum p (kg-m/s)= mass * velocity

say moving car=1 000 kg, velocity = 10 m/s then p = 1 000*10= 10 000 kg-m/s

say still car = 2 000 kg, velocity = 0 m/s then p = 2 000* 0 = 0 kg-m/s

total momentum prior to collision = 10 000 + 0 = 10 000 kg-m/s

momentum after collision = 10 000 kg-m/s

mass now = 1 000 kg+2 000 kg = 3 000 kg

10 000 = 3 000 kg* velocity m/s

10 000/3 000 = velocity

3.33 m/s = velocity after collision

an impulse is a force applied over time , momentum is exclusive of external forces and a perfect collision is implied