Answer:
that's because....
group 1 (e.g Na, K) those tend to lose one electron to gain noble gas electron configuration.
they can achieve that by just losing one electron from their outer shell.
as you go down the group 1, element gets bigger in size, which means there is more space between nucleus (which is in center of atom) and electron of outer shell. the more far away they are the less attraction force between them.
so its easier for potassuim to lose one electron than for lithuim.
so that means potassium will easily give up 1 electron to react with non metal or other element therefore it is more reactive than lithuim
but in case of non metal, the opposite happens but simple to understand.
as you go down the group 7 (halogen- Cl, Br, I) element will get bigger therefore force between nucleus and outer electron is getting smaller. they have to gain 1 electron in order to fill the outer shell (to gain noble gas electron configuration.)
as florine is more smaller in size than clorine it is more reactive because florine has more tendency to pull extra electron from metal or other element towards its side. so it easily gain 1 electron to react.
A. is decomposition so HCL = H2 + Cl2
not balanced cause hcl needs 2
2HCL = H2 + Cl2
balanced
b. Br2 + Al-i = AlBr3 + I2 single rep.
not balanced since br need 3 so watch carefully cause many changes needed
3Br2 + Al-i = AlBr3 + I2 not right is unbalanced so make it 2
3Br2 + Al-i = 2AlBr3 + I2 now left Al is unbal. so make 2 there
3Br2 + 2Ali = 2AlBr3 + I2
Balanced
C. Na + S = Na2S synthesis reaction is not bal. left Na needs 2
2Na + S = Na2S balanced.
Answer:
The photoelectric effect is the emission of electrons when electromagnetic radiation, such as light, hits a material. Electrons emitted in this manner are called photoelectrons.
Based on the wave model of light, physicists predicted that increasing light amplitude would increase the kinetic energy of emitted photoelectrons, while increasing the frequency would increase measured current.
It is going through a physical change
