Question

write down three major differences between mandellev's periodic table and modern periodic table ?​

Answer 1

i hope it is useful for you thanks

Answer 2

Difference are

1- Mendleev table is base on increasing atomic masses but modern is based on atomic number

2- At that time noble gases were not discovered so it was not there in Mendleev table but in modern table it assigned at a special place

3-He put cobalt and nickle in the same slot without giving any reason but now this problem is solved