Chemistry Chapter 6

What is chemical formula made up of?

chemical symbols that indicate the elements present

subscript indicating the number of atoms of each element present

What does the chemical symbols indicate?

It indicates what are the elements present

What does the subscript indicate?

It indicates the number of each element present

What are the 3 types of elements that can exist?

Monoatomic elements

Diatomic molecules

Polyatomic molecules

What are monoatomic elements?

Monoatomic elements are elements that exist as uncombined atoms

What group number exists as monoatomic elements?

Group 18

Why can Group 18 elements exist as monoatomic elements?

This is because they are generally unreactive as they have full valence shells of electrons

What are diatomic molecules?

Diatomic molecules are molecules that exist as two chemically combined atoms

What are some examples of diatomic molecules?

Hydrogen

Oxygen

Fluorine

Iodine

Bromine

What are polyatomic molecules?

Polyatomic molecules are molecules that exist as three or more chemically combined atoms

What are some examples of polyatomic molecules?

Sulfur

Phosperous

Ozone

What are compounds made up of?

Compounds are made up of atoms of elements that are chemically combined

Compouds have fixed formulae, while mixtures do not have fixed formulae. (T/F)

True

What are some examples of compounds?

Ammonia

Copper (II) sulfate

Sodium hydroxide

Ethanoic acid

Hydrochloric acid

What can the valency of an element be referred to?

The valency of an element can be referred to as the number of electrons that must be lost, gained, or shared for that element to obtain a stable, noble gas electronic configuration

What is the valency of an ion?

The valency of an ion is its charge without a sign

How can we find out valencies from group numbers?

Group 1 and 17 have a valency of 1. Group 2 and 16 have a valency of 2. Group 13 and 15 have a valency of 3. Group 14 have a valency of 4

How can we find out valencies from Roman numerals?

Iron(III) has a valency of 3, which iron(II) has a valency of 2

Why does silver have a fixed charge?

Silver is in the transition metal block, but it forms only one common ion so its charge is fixed, and its valency is 1

What are polyatomic ions?

Polyatomic ions are ions which are made up of more than one atom covalently bonded together

Polyatomic ions carry …

overall charges, and their overall valencies is the charge on the ions.

What are some common polyatomic ions and their valencies?

Ammonium: 1, Sulfate: 2, Carbonate: 2, Hydroxide: 2, Nitrate: 2, Phospate: 3

What is the simplest way to construst a chemical formula?

The crossing method

What side are reactants placed on in a word equation?

The left side

What side are products placed on in a word equation?

The right side

What are common state symbols?

liquid(l)

solid(s)

gas(g)

aqueous(aq)

What is the state symbol for most acids and bases?

Aqueous because they are usually used dilted

What does a balanced chemical equation show?

A balanced chemical equation shows the expected ratio of reactants to products

Atoms are conserved in physical and chemical reactions in a balanced equation. (T/F)

True

What is an ionic equation?

An ionic equation shows the ions that take part in the reaction, involving at least one aqueous reactant that is usually an ionic compound

What are spectator ions?

Spectator ions are substances that remain unchnged in their physical state or charge do not take part in the reaction

Why are aqueous chlorine and aqueous iodine special?

They do not need to be split into ions when dissolved in water. They have undergone a change in physical state, but they remain unchanged as part of the ionic equation.