Describe the basic patterns in the Periodic Table related to: Atomic number
valence electrons
valence shells
chemical properties/reactivity

Which part of earth’s surface receives the most direct rays from the sun? a) equator b) ocean c) poles d) mountains

Sum of brother and sisters age is 26. four times the brothers age is subtracted from three times the sisters age, the difference is 8. what are the ages of the brother and sister?

An atom of element x has one more shell of electrons than an atom of beryllium, but it has one less valance electron than beryllium. which element is x