Compounds and Formulae Flashcards
What are ionic compounds
Ionic compounds are compounds made up from metal and non-metal elements that are joined together
What does the formula of an ionic compound give us
The formula of an ionic compound gives us the simplest ratio needed between positive and negative ions to have zero overall charge
How is sodium (Na+) chloride ( Cl-) formed?
The sodium atom(2.8.1) loses the electron in its outer shell in an attempt to acquire a full outer shell. The lost electron goes to the chlorine atom (2.8.7) which needs only one electron to complete a full outer shell. Both ions are now more stable, as they have a full outer shell. A neutral compound is formed.
What is valency
Valency is the amount of electrons needed to be lost or gained by an atom in order to acquire a full outer shell.
What is the relationship between the valency of an element and the charge of the ion formed
The valency is equal to the charge of the ion
How can we find the chemical formula of a compound
In order to find the formula of a compound, we first need to find the charge of each element involved. Then, we need to swap the numbers of the charges in order to get the formula and a neutral compound
Write down the four polyatomic ions and their formulas
Carbonate: CO3 2-
Hydroxide: OH -
Nitrate: N03 -
Sulfate: S04 2-
Write down all the diatomic elements
Iodine (I2), Bromine (Br2), Chlorine (Cl2), Fluorine (F2), Oxygen (O2), Nitrogen (N2), Hydrogen (H2)
Write the formula of Ammonia
NH3
Write down the formula of Methane
CH4
Write down the formulae of 3 acids
Hydrochloric acid: HCl
Sulfuric acid: H2SO4
Nitric acid: HNO3
How do we write a chemical equation
The first step is to write a word equation showing the reactants and the products. The next step is to write the formula for each of the reactants and products. Lastly, balance the equation so there is an equal number of atoms of each element on each side
