Gas
Two or more atoms of different elements joined together form a compound. If it is a metal and non-metal (for example sodium and chlorine), they are ionically bonded. If it is two non-metals (for example methane is carbon and hydrogen), they are covalently bonded.
Nitrogen, Oxygen, Flourine, and Chlorine. Bromine and Iodine are both joined together in their own molecule, but Bromine is a liquid and Iodine is a solid. The way i remember these 'diatomic' (they are elements in pairs of two atoms to a molecule) elements is by, NOFClBrI. Sticks in your head and they form an upside down 'L' shape in the periodic table.
a molecule
If I undersstand your question correctly, a group of atoms that is joined by a covalent bond, and is neutral would be called a non-polar molecule.
Diatomic oxygen is a diatomic molecule joined by a double covalent bond.
A molecule.
Usually you would name chlorine as an element, and not an atom. An element has atoms, and there can be a chlorine atom. But according to terminology, you would name it as an element.
Two or more atoms of different elements joined together form a compound. If it is a metal and non-metal (for example sodium and chlorine), they are ionically bonded. If it is two non-metals (for example methane is carbon and hydrogen), they are covalently bonded.
lactose
Nitrogen, Oxygen, Flourine, and Chlorine. Bromine and Iodine are both joined together in their own molecule, but Bromine is a liquid and Iodine is a solid. The way i remember these 'diatomic' (they are elements in pairs of two atoms to a molecule) elements is by, NOFClBrI. Sticks in your head and they form an upside down 'L' shape in the periodic table.
Lots of smaller alkene molecules are joined together to form a long chain molecule and create a polymer.
a molecule
If I undersstand your question correctly, a group of atoms that is joined by a covalent bond, and is neutral would be called a non-polar molecule.
Molecule
Diatomic oxygen is a diatomic molecule joined by a double covalent bond.
Either molecule or compound
A particle composed of one or more atoms is called a molecule