Answer:
Explanation:
An atom is the smallest unit of an element that can take part in a chemical reaction. Atoms (and there corresponding symbols) mentioned in the question are
Lithium ⇒ Li
Carbon ⇒ C
Nitrogen ⇒ N
Potassium ⇒ K
Oxygen ⇒ O
Iron ⇒ Fe
Chlorine ⇒ Cl
A compound is substance that contains two or more atoms that are chemically combined and can be represented with a chemical formula. The compounds (and there corresponding formula) mentioned in the question are
Water ⇒ H₂O
Edible salt (sodium chloride) ⇒ NaCl
Chalk (calcium carbonate) ⇒ CaCO₃
Lime (calcium oxide) ⇒ CaO
Iodides (such as sodium iodide and potassium iodide) ⇒ NaI and KI respectively
1 elements
2 they have same number of valence electrons
3 period
Answer:
Halogens always form anions, alkali metals and alkaline earth metals always form cations. Most other metals form cations (e.g. iron, silver, nickel), whilst most other nonmetals typically form anions (e.g. oxygen, carbon, sulfur).
Explanation:
Examples: Sodium (Na+), Iron (Fe2+), Ammonium (NH4
