The number of protons determines the identity of the element.  If a selenium atom could lose a proton, it would no longer be a selenium atom.  The new atomic number would be 33, arsenic.  

Arsenic is a component in rat poison…NO

Determine the # of Protons (P⁺), Neutrons (N^o), Electrons (E^-)

⁵⁶Fe 

P⁺ 26

N^o  30

E^- 26

Determine the # of Protons (P⁺), Neutrons (N^o), Electrons (E^-)

¹³¹I

P⁺ 53

N^o 78

E^- 53

Determine the # of Protons (P⁺), Neutrons (N^o), Electrons (E^-)

¹³⁸Ba²⁺

P⁺ 56

N^o 82

E^- 54

Determine the # of Protons (P⁺), Neutrons (N^o), Electrons (E^-)

³¹P^3-

P⁺ 15

N^o 16

E^- 18

 Identify the following element as metal, non-metal, or metalloid

Fe

 Identify the following element as metal, non-metal, or metalloid

As

 Identify the following element as metal, non-metal, or metalloid

N

 Identify the following element as metal, non-metal, or metalloid

I

 Identify the following element as metal, non-metal, or metalloid

Cs

Atoms that lose electrons become positively charged and are termed CATIONS. 

Atoms that gain electrons will become negatively charged and are called ANIONS

B

Si

Ge

As

Sb

Te

Po

At

Metals are good conductors of heat and electricity.

They typically are shiny and are malleable and ductile.