Answer:
O, S, Te
Cl, Br, Se
Explanation:
Main group elements have an electronegativity that increases across a period (from left to right) and decreases down a group.
Each atom has its own value which you can find on the electronegativity chart.
Metals have low values
Nonmetals have high values
I'm your case:
O = 3.5
S = 2.5
Te = 2.1
Cl = 3.0
Br = 2.8
Se = 2.4
Ba! It is a metal and wants to lose 2 electrons ASAP
Answer:
positron
Explanation:
A positron is a particle produced when a proton is transformed into a neutron. Anti neutrinos are ejected from the nucleus to balance spins.
Positron emission increases the Neutron/Proton ratio. When a nuclide undergoes positron emission, the atomic number of the daughter nucleus is one unit less than that of the parent nucleus hence it is found one place before its parent in the periodic table.