Answer:
See explanation
Explanation:
1 ) Al has physical and chemical properties, similar to Boron, because It's also part of group 13, also called the boron group. The elements are characterized by having three valence electrons.
2) Lithium is in group 1. This means it has 1 valence electron.
Nitrogen has 7 electrons. The first shell can only have 2 electrons, so the second and outer shell has 5 electrons. Those 5 electrons are the 5 valence electrons;
Neon is a noble gas, it's in the stable noble gas configuration. This means it has 8 valence electrons.
Oxygen = non-metal because it's a gas
Silicon = metalloid
Helium = non-metal because it's a gas
Arsenic = metalloid
Sodium = it's an (alkali) metal, It is physically silver colored and is a soft metal of low density. Pure sodium is not found naturally on earth because it is a highly reactive metal
Chlorine = non-metal
Tin = Is a soft, ductile and highly crystalline silvery-white metal
Boron = it does conduct electricity. Its chemical properties are mostly, but not entirely, and non-metallic
lead = is a heavy metal that is denser than most common materials
Radon = metalloid
Cesium = It is a soft, silvery-golden alkali metal
Carbon = non metal
Period
⇒ Horizontal from left to right
⇒ same number of atomic orbitals
⇒period = row
Group
⇒ vertical colums
⇒same number of valence electrons
⇒ same physical and chemical properties
