Additional Science: Chemistry (II) Flashcards
(125 cards)
Draw and label an atom

What are the masses and charges of these parts of an atom
Proton
Neutron
Electron
Protons = +ve (mass 1)
Neutrons = neutral (mass 1)
Electrons = -ve (mass 1/2000th)
Why do atoms usually have no overall electrical charge?
Atoms usually have no overall charge because they have equal numbers of protons (+ve) and electrons (-ve), which cancel one another out
All atoms of a particular element (e.g. carbon) all have the same number of what?
Protons
What are the following numbers called?

a = relative atomic mass
b = atomic number
What do the numbers tell you about the atom?

a = relative atomic mass – the number of protons and neutrons in the atom
b = atomic number – the number of protons (usually the same as the number of electrons)
What is an alloy and why are they used?
Give some examples
Alloys are mixtures of metals with other elements, e.g. iron + carbon → steel
They have a combination of properties, e.g. bronze, brass, steel etc…
What is a smart alloy and why are they used (shape-memory)?
Give some examples
Smart alloys can return to their original shape after being deformed – e.g. glasses and braces
What do these terms means: -
Element
Compound
Mixture
Element – pure substance with only 1 type of atom (e.g. gold)
Compound – 2 or more elements chemically bound (e.g. carbon dioxide)
Mixture – more than 1 element or compound not chemically bound (e.g. air)
What are the symbols for the following atoms: -
Oxygen
Nitrogen
Chlorine
Hydrogen
Sodium
Copper
Potassium
Helium
Calcium
Zinc
Iron
Carbon
Oxygen (O)
Nitrogen (N)
Chlorine (Cl)
Hydrogen (H)
Sodium (Na)
Copper (Cu)
Potassium (K)
Helium (He)
Calcium (Ca)
Zinc (Zn)
Iron (Fe)
Carbon (C)
What happens to atoms when they chemically react to form a compound?
They share, give away, or take electrons
What are the names of these compounds, and which atoms are found in them?
H2O
CaCO3
H2SO4
HCl
CO2
Water (H2O)
Calcium carbonate (CaCO3)
Sulfuric acid (H2SO4)
Hydrochloric acid (HCl)
Carbon dioxide (CO2)
What is an isotope?
An isotope is an atom with a different amount of neutrons
Use the periodic table to draw the electron structure of the following: -
Neon
Calcium
Sodium
How can you tell which group these atoms are in?
The number of electrons in the outer shell is the same as their group number

How many electrons can occupy the 1st and 2nd shell (energy level) of an atom?
2 in the 1st shell and 8 in the 2nd shell
The electron structure of sodium can be represented as 2,8,1 – what does this mean?
Represent these atoms: -
Fluorine
Oxygen
Potassium
Magnesium
2,8,1 means 2 electrons in the 1st shell, 8 electrons in the 2nd shell and 1 electron in the 3rd shell
Fluorine = 2,7
Oxygen = 2,6
Potassium = 2,8,8,1
Magnesium = 2,8,2
Define these terms: -
Element
Compound
Mixture
Element – a pure substance made from 1 type of atom only
Compound – 2 or more elements chemically bound
Mixture – 2 or more elements or compounds mixed together which are not chemically bound
What happens to the electrons of 2 atoms when they chemically react?
During a chemical reaction electrons are either given away, taken, or shared
What is an ion?
How are +ve ions formed?
How are -ve ions formed?
An ion is an atom with a charge
+ve ions have lost electrons
-ve ions have gained electrons
Explain how the following atoms become ions (will they be +ve or –ve)?
Potassium
Magnesium
Chlorine
Oxygen
Potassium – loses 1 electron (K+)
Magnesium – loses 2 electrons (Mg2+)
Chlorine – gains 1 electron (Cl-)
Oxygen – gains 2 electrons (O2-)
Use diagrams to show how these atoms for ionic bonds: -
Sodium + Chlorine

Describe and use a diagram to show the structure of ionic compounds
Ionic compounds have a giant structure – they are bonded to 6 other ions by electrostatic bonds

What are the melting and boiling points of ionic compounds like?
Why is this?
Ionic compounds have high melting points and boiling points – to melt them you have to supply enough energy to break the 6 bonds attached to each ion
What happens to the electrons when atoms form ionic bonds and covalent bonds?
Which is the strongest?
Ionic bonds – 1 atom loses electrons and another gains electrons
Covalent bonds – electrons are shared
An individual covalent bond is stronger than an ionic bond
















