Answer:
When white glue is in the bottle, there's not enough air inside the bottle to cause the water to evaporate to make the glue sticky. Basically, the bottle holds the glue from the air and keeps the glue from going everywhere.
JJ Thomson proved John Dalton's theory wrong, as Thomson discovered the electron. This showed that there were particles that were smaller than an atom, despite Dalton claiming that the atom is the smallest unit of matter.
Answer:
Electrons arrangement change is almost constant down the group, hence nuclear charge is almost constant.
But the energy levels on which electrons are arranged increase down the group, hence shielding or screening effect increases.
