The answer is the first one!!! have a WONDERFUL day!!
C. The neutron number.
An element is determined based on how many protons has, if the protons number change then you got a new element.
If the number of neuron change you got the same element except it will be a bit heavier or lighter if you are gaining or loosing neutrons. Those variations of an element are called the isotops of the element.
The protons and neutrons toghether form the nucleus of the atom that is heavy and dense as an elephant.
The electrons are light as fleas and stay on the shels of around the nucleus and if they are more then the number of protons they make the atom negatively charged and vice versa.
Answer:
1) C
2)A
3)D
Explanation:
London forces are common to all molecules, it results from momentary shifts in electron distribution in molecules. When molecules possess a permanent dipole, dipole-dipole interaction is the dominant intermolecular force. However, for compounds in which hydrogen is bonded to highly electronegative element, hydrogen bonding is important.
