Heating a substance causes molecules to speed up and spread slightly further apart, occupying a larger volume that results in a decrease in density. Cooling a substance causes molecules to slow down and get slightly closer together, occupying a smaller volume that results in an increase in density.
From: www.middleschoolchemistry.com
Answer :
(A) Br₂ (s) : molecular solids
(B) AgCl (s) : ionic solids
(C) S (s) : atomic solids
(D) CH₄ (s) : molecular solids
Explanation :
Molecular solids : It is defined as the solids in which they are held together by covalent forces, dipole interactions as attractive forces etc.
Ionic solids : It is defined as the solids in which the atoms composed with oppositely charged ions.
Atomic solids : It is defined as the solids in which the molecules are held together by covalent forces and also includes pure substance.
(A) Br₂ (s)
It is molecular solids because they are held together by covalent forces.
(B) AgCl (s)
It is ionic solids because in this atoms composed with oppositely charged ions.
(C) S (s)
It is atomic solids because it is a pure substance.
(D) CH₄ (s)
It is molecular solids because they are held together by covalent forces.
Answer:
b) Gain or lose electrons
Explanation:
An ion is an electrically charged particle. For an atom to be charged, it must have gained or lost electron in the process and therefore, it becomes an ion.
The loss or gain of electrons is what makes an atom charged and eventually becomes an ion.
A positively charged ion is one that has lost an electron and it is called a cation. In such an ion, the number of electrons are lesser than those of protons. This is why they are cations
A negatively charged ion is one that has gained electrons. They are called anions. In such an ion, the number of electrons are greater than that of protons.
A or D I think but go with A it makes more since