Wave nature of electrons was demonstrated by :
Schrodinger
De-Broglie
Davisson and Garmer
Heisenberg
A gas can expand from 100 mL to 250 mL under a constant pressure of 2 atm .The work done by gas is :
30.38 joule
25 joule
5 k joule
16 joule
If the r.m.s. speed of a gaseous molecule is x m/sec at a pressure P atm , then what will be the r.m.s. speed at a pressure 2P atm and constant temperature ?
x
2x
4x
x/4
How does the ionisation energy of 1st group elements vary ?
Increases down the group
Decreases down the group
Remains unchanged
Variation is not regular
B.
Decreases down the group
Ionization energy of Ist group elements decreases down the group because in groups from top to bottom atomic size increases .Due to increase in atomic size ,the nuclear attraction of outer electron is reduced .They easily removed from valence orbital .So ionization energy is reduced from top to bottom in a group .