Melting
Melting is a change in property of matter from solid to liquid
Matter is anything that occupies space and has mass. Thus, there are fundamentally three types of matter which is solid liquid and gas. But why do gases and liquids diffuse and not solids? It is because of the molecular structure of these components of matter. If we examine the molecular structure of gas the molecules are highly scattered and liquid has also almost the same structure as mediocrely scattered that these particles can easily slip through other substances unlike solid which is entirely intact. <span> </span>
A. Protons, neutrons, and electrons
The principal quantum number, <span>nn</span>, designates the principal electron shell. Because n describes the most probable distance of the electrons from the nucleus, the larger the number n is, the farther the electron is from the nucleus, the larger the size of the orbital, and the larger the atom is. n can be any positive integer starting at 1, as <span><span>n=1</span><span>n=1</span></span> designates the first principal shell (the innermost shell). The first principal shell is also called the ground state, or lowest energy state. This explains why <span>nn</span> can not be 0 or any negative integer, because there exists no atoms with zero or a negative amount of energy levels/principal shells. When an electron is in an excited state or it gains energy, it may jump to the second principle shell, where <span><span>n=2</span><span>n=2</span></span>. This is called absorption because the electron is "absorbing" photons, or energy. Known as emission, electrons can also "emit" energy as they jump to lower principle shells, where n decreases by whole numbers. As the energy of the electron increases, so does the principal quantum number, e.g., n = 3 indicates the third principal shell, n = 4 indicates the fourth principal shell, and so on.
A. 1 proton and 1 neutron
