Topic 4 Atoms Flashcards
What is an element?
An element is a pure substance, the atoms of which cannot be made into a simpler substance. An element is made up of only one kind of atom.
What is made of matter?
Everything
What is matter?
Matter is anything that has mass and takes up space.
What are atoms?
Atoms are the building block of matter.
How big are atoms?
Atoms are extremely small.
Why can’t elements be changed into another element?
It is because the atoms of every element are unique, and they are made up of only one type of atom.
What does it mean if an element is chemically unique?
This means that a chemical reaction cannot alter the atoms of an element.
How is the periodic table arranged?
It is arranged into a grid pattern with seven horizontal rows and 18 vertical columns.
Where does the word ‘atom’ come from?
‘Atom’ comes from the Greek word atomos, which means ‘uncuttable’.
What is an atom made up of?
Subatomic particles
What is the centre of an atom called?
The nucleus
What is the nucleus made up of?
Protons and Neutrons
How are protons charged?
They have a positive charge.
How are neutrons charged?
They are neutrally charged.
What is the circling cloud around the nucleus called?
They are called electrons.
How are electrons charged?
They have a negative charge.
How is an atom charged?
It has a neutral charge.
How big is the nucleus in relation to the cloud of electrons?
The nucleus is as a marble would be in the middle of a football stadium, although the nucleus makes up most of the mass of the atom.
What is a scientific model?
A scientific model is a representation of an idea of how something works.
How do we determine the amount of protons in an atom?
The amount of protons is equal to the atomic number.
How do we determine the amount of electrons in an atom?
The amount of electrons is equal to the atomic number.
How do we determine the amount of neutrons in an atom?
We subtract the atomic number from the atomic weight.
What is a pure substance?
A pure substance consists of only one type of particle.
What is a compound?
A compound is 2 or more atoms fused together through a chemical reaction in a fixed ratio.
What are examples of pure substances?
Elements and compounds.
What properties help us to find out more about a substance?
Phase Conductivity Solubility Density Magnetism Melting point Boiling point
What does the phase tell us about a substance?
It tells whether the substance is a solid, a liquid or a gas.
What does the conductivity tell us about a substance?
Conductivity tells us whether or not the substance can allow an electric current through it.
What does the solubility tell us about a substance?
The solubility tells us whether the substance can dissolve in water.
What does the density tell us about a substance?
The density tells us how closely the particles are packed together.
What does the magnetism tell us about a substance?
It tells us whether or not a substance is magnetic. It also tells us whether the substance contains, Copper, Nickel or Cobalt atoms, since those are the only elements that are magnetic.
What does the melting point tell us about a substance?
It tells us the temperature at which the substance melts or freezes.
What does the boiling point tell us about a substance?
It tells us the temperature at which a substance boils or condenses.
How can we tell whether a substance is pure?
If we know the melting or boiling point of a substance, we can test whether it is pure.
What is a molecule?
A molecule is two or more atoms that have bonded together.
How are compounds represented?
They are represented by the atomic symbols of the elements that create the compound. After the symbol is a subscript number that shows how many atoms of that particular element are in the compound.
How are compounds spoken?
The name of the first element is not changed. If a metal is part of the compound, then the name of that metal is said first. If you join two elements, then the second element has ‘ide’ as a suffix. If you join three elements, the last element has ‘ate’ as a suffix.
What is the periodic table?
The periodic table is a representation of all the elements ever discovered by humans.
What is a chemical bond?
A chemical bond is a strong force of attraction that holds different atoms together.
What does the word synthesis mean?
It refers to the joining together of two atoms.
What does the word decomposition mean?
It refers to the breaking down of chemical bonds in atoms.
What is a chemical decomposition?
It is a chemical reaction that breaks chemical bonds between atoms.
What are the decomposition reactions?
Electrolysis and thermal decomposition
What is electrolysis?
Electrolysis is the decomposition reaction that uses an electrical current to split atoms apart.
What is thermal decomposition?
Decomposition by heating.
What is an endothermic reaction?
An endothermic reaction is when heat is put IN to the experiment. It is usually a decomposition reaction.
What is an exothermic reaction?
An exothermic reaction is when heat comes OUT of an experiment, it is is usually a synthesis reaction.
What is a mixture?
A mixture is when different types of atoms move in between each other, without a chemical reaction and in an unfixed ratio.
What happens to the particles in a mixture?
They keep most of their properties.
How do we separate particles in a mixture?
We can use physical methods.
What methods can be used to separate mixtures?
Hand sorting Sieving Using a magnet Filtration Evaporation Distillation Chromatography
What would be the best way to separate a mixture of:
Sand and salt
Evaporation and then filtration
What would be the best way to separate a mixture of:
Sand and iron filings
Using a magnet
What would be the best way to separate a mixture of:
Ethanol and water
Distillation
What would be the best way to separate a mixture of:
Rice and cake flour
Sieving
How are atoms drawn?
The electrons are shown as spheres with a negative sign displayed on them to show that they are negatively charged
The electrons must be drawn around the nucleus of the atom
The orbits of the electrons must be drawn
The protons are represented as spheres with a plus sign to show that they are positive
The protons must be part of the nucleus with the the neutrons
The neutrons are drawn as spheres with no symbols on them
Only two electrons can be shown in the first orbit
Only eight electrons can be shown in the second orbit
Which wire that connects to a battery is the negative wire, and which wire is the positive wire?
Red is positive
Black is negative
Who was Dimitri Mendeleev?
He was the man to order the elements in the periodic table.
