C1.1 - Everything in the Specification

All [blank_start]substances[blank_end] are made up of [blank_start]atoms[blank_end]. A [blank_start]substance[blank_end] that is made of only one type of [blank_start]atom[blank_end] is called an [blank_start]element[blank_end]. There are about one [blank_start]hundred[blank_end] different [blank_start]elements[blank_end], and they are arranged in the periodic [blank_start]table[blank_end]. The [blank_start]groups[blank_end] of the periodic [blank_start]table[blank_end] contain [blank_start]elements[blank_end] with [blank_start]similar[blank_end] properties.

What do elements form when they react?

Atoms of each element are represented by a chemical symbol.

Atoms are made up of a small central [blank_start]nucleus[blank_end], which is made up of [blank_start]protons[blank_end] and [blank_start]neutrons.[blank_end] Around this, there are [blank_start]electrons[blank_end] which move in specific [blank_start]energy levels[blank_end] in an 'orbit'. They are often called [blank_start]electron shells[blank_end].

Fill in the table to complete the relative masses and charges of subatomic particles.

Why does an atom have no overall charge on it? Because the number of e[blank_start]lectrons[blank_end] is equal to the number of [blank_start]protons[blank_end], and the [blank_start]neutrons[blank_end] do not have a [blank_start]charge[blank_end], so there is no overall [blank_start]charge[blank_end] on an atom. How are different ions formed? P[blank_start]ositive[blank_end] ions are formed by [blank_start]removing[blank_end] electrons; [blank_start]negative[blank_end] ions are formed by [blank_start]adding[blank_end] electrons.

All atoms of a particular element have the same number of protons.

[blank_start]ATOMIC[blank_end] NUMBER - The number of [blank_start]protons[blank_end] in an atom of an element. [blank_start]MASS[blank_end] NUMBER - The sum of the [blank_start]protons[blank_end] and n[blank_start]eutrons[blank_end] in an atom.

What are the elements in Group 0 of the periodic table called, and how many electrons do they have in their outer energy level?

Noble gases are unreactive because they have full outer shells.

Compounds formed from [blank_start]metals[blank_end] and n[blank_start]on-metals[blank_end] consist of [blank_start]ions[blank_end]. They are held together by [blank_start]ionic[blank_end] bonds. Compounds formed from n[blank_start]on-metals[blank_end] and n[blank_start]on-metals[blank_end] consist of [blank_start]molecules[blank_end]. They are held together by [blank_start]covalent[blank_end] bonds.

Balance the following equations by picking the correct numbers of each reactant and product. 1) [blank_start]_[blank_end]Fe₂O₃(s) + [blank_start]_[blank_end]HCl(aq) ==> [blank_start]_[blank_end]FeCl₃(aq) + [blank_start]_[blank_end]H₂O(l) 2) [blank_start]_[blank_end]Fe(s) + [blank_start]_[blank_end]O₂(g) ==> [blank_start]_[blank_end]Fe₃O₄(s) 3) [blank_start]_[blank_end]Al(s) + [blank_start]_[blank_end]H₂SO₄(aq) ==> [blank_start]_[blank_end]Al₂(SO₄)₃(aq) + [blank_start]_[blank_end]H₂(g)

The law of [blank_start]conservation[blank_end] of [blank_start]mass[blank_end] states that no [blank_start]atoms[blank_end] are [blank_start]lost[blank_end] or [blank_start]gained[blank_end] during a chemical reaction, so the mass of the [blank_start]products[blank_end] is equal to the mass of the [blank_start]reactants[blank_end].