Hello, Tulips2411!!
A) Physical change doesn't change what the substance is. The actual physical property can change (appearance). For a chemical change, a new substance is formed and energy is given off or absorbed.
B) Metallic is the level of reactivity of a metal. Increased going down in a group. Non-metallic is the tendency to accept electrons during chemical reactions. They are increased from left to right in the periodic table.
C) Atoms are composed of protons, neutrons, and electrons. H+ (Hydrogen) atoms has 1 proton and 1 electron. Atoms that are the same element but have different number of neurons are known or referred to an isotope.
D) Electron affinity is energy that can change when a neutral atom attracts an electron to become a negative ion. Electronegativity is the ability of an atom in a molecule to draw bonding electrons to itself.
I hope I helped!! Have a great day!! :)
