Unit 1 Flashcards
What do compounds end in if they don’t contain water?
-Ide
What do compounds end in if containing oxygen??
-ite OR -ate
What’s everything in the world made from?
About 100 elements
What’s a period?
A row of elements in the periodic table
What’s a group?
A column of elements in the period table
What are the different ways elements are classified?
Naturally-occurring/ made by scientist
Solid/liquid/gas
Metal/non-metal
What are the groups in the periodic table? (3)
Halogens
Alkali metals
Noble gases
What do the elements in any one group show?
Similar chemical properties
What are the noble gases a family of?
Very unreactive elements
What are the alkali metals a family of?
Very reactive metals
What are the halogens a family of?
Very reactive non-metals
Where are the transition metals found?
Between groups 2&3 in the periodic table
When are compounds found?
When elements react together
What do all chemical reactions involve?
The formation of one more new substances
What can chemical reactions be identified from? (4)
Energy change Changes in appearance of substances: Colour change Gas evolved Precipitate formed
What do exothermic reactions do?
Release Energy to the surroundings and the products have a less chemical energy than the reactants
When do mixtures occur?
When two or more substances come together without reacting
What is air?
A mixture of gases
What’s the test for oxygen?
If it delights a glowing splint
What to endothermic reactions do?
Take in energy from the surroundings and the products have more chemical energy than the reactants
What all does an atom contain?
A nucleus with protons and neutrons inside and electrons moving around outside the nucleus
Why is an atom neutral?
Bc the protons and electrons are equal
Approximately How heavy are protons and neutrons?
Mass of one atomic mass unit
What’s the mass of an electron?
Virtually no mass
How are the electrons in an atom arranged?
In energy levels
Atoms of different elements have a different number of protons, what’s the name for it?
Atomic number
What can atoms achieve in forming bonds?
A stable electron arrangement
Which bond shares pairs of electrons?
Covalent bonds
What is a covalent bond a result of?
Two positive nuclei being held together by their common attraction for the shared pair of electrons
What are covalent bonds?
Strong forces of attraction
What bond is formed when the attraction of the atoms for the bonded electron is different?
Polar covalent
Which bond is highly polar in water?
Covalent
How are ionic compounds formed?
When metals combine with non metals
What is ionic bonding?
The electrostatic force of attraction between oppositely charged ions
What is metallic bonding?
The electrostatic force of attraction between positively charged ions and delocalised electrons
What is a molecule?
A group of atoms held together by covalent bonds
What’s a diatomic molecule?
Made up of two atoms
What are the diatomic molecules? (5)
Hydrogen Nitrogen Oxygen Carbon monoxide The halogens
What can covalent substances consist of?
Discrete molecules
What are the bonds between molecules weaker than?
The covalent bonds within molecules
What does a covalent network consist of?
A giant lattice of covalent my bonded atoms
What does a metallic structure consist of?
A giant lattice of positively charged ions and delocalised outer electrons
What are all the conductors of electricity because they contain free electrons? (2)
Metal elements (solid/liquid) Carbon (graphite)
What doesn’t conduct electricity since they are made up of molecules which are uncharged?
Covalent substances (solid/liquid/solutions)
What’s an electric current?
A flow of charged particles
What’s electrolysis?
The flow of ions through a solution and molten compounds (electrolytes)
What must be used if the products of electrolysis are to be identified?
d.c. Power supply
What can the results of electrolysis experiments be illustrated by?
The migration of coloured ions
What compound is usually soluble in water?
Ionic compounds
What do discrete covalent substances have? (Mp/bp)
Low melting and boiling points
What may covalent substances which are insoluble in water dissolve in?
Other solvents
What do metals, ionic compounds and covalent network substances have? (Mp/bp)
High melting and boiling points
What does electrolysis do?
Chemically changes the electrolyte and may lead to the break up of compound
What conducts electricity only when dissolved in water or molten?
Ionic compounds
