5.3 Elements & 5.4 Periodic Table Flashcards
What is an element?
A substance that contains only one type of atom.
What is a compound?
A pure substance made from 2 or more elements chemically bonded together.
What is a molecule?
A group of 2 or more atoms chemically joined together. Can be elements or compounds.
What is an ion?
An atom that has a different number of protons and electrons and is therefore charged.
What is an isotope?
An atom with the same number of protons but a different number of neutrons. An isotope of an element is still the same element.
What is salt?
Salt is a compound that contains atoms of sodium and chlorine, its scientific name is sodium chloride.
Why does water have a higher boiling point than hydrogen?
It takes more energy to separate water molecules from each other than to separate hydrogen molecules.
What is an atom?
The smallest part of an element that can exist naturally.
Why are carbon compounds different?
The properties of a compound depend not only on the elements in it, but also on the relative number of atoms of each element in the compound.
How do we name compounds involving oxygen?
- Compounds made up of oxygen and another element have two-word names, the second word is oxide (e.g. aluminium + oxygen becomes aluminium oxide).
- Some elements form more than one type of oxide (e.g. 1 carbon atom and 1 oxygen atom becomes oxygen monoxide, whereas 1 oxygen atom and 2 carbon atoms becomes carbon dioxide).
How do you name compounds of a metal and non-metal?
In any compound of a metal with a non-metal, the end of the neme of the non-metal becomes -ide, for example, sodium and chlorine becomes sodium chloride
How do you name compounds with more than 2 elements?
Many compounds are made up of atoms of more than 2 elements, for example:
1. A hydroxide includes hydrogen and oxygen atoms.
2. A nitrate includes nitrogen and oxygen atoms.
3. A sulfate includes sulfur and oxygen atoms.
4. A carbonate includes carbon and oxygen atoms.
What is a polymer?
Polymers are long chains of molecules. A polymer molecule has identical groups of atoms, repeated many times, they are made from smaller molecules called monomers.
What is polymerisation?
man-made (synthetic polymers) are made by joining lots of monomers together to make very long molecules (polymers). This process is called polymerisation, polymers are made from chemicals that are obtained from crude oil.
Why are natural polymers useful?
Plants and animals make natural polymers including wool and rubber.
Sheep make wool and the wool fibres trap air between them. This means wool traps heat making it suitable for jumpers and socks.
Rubber trees produce rubber, which has long bendy molecules that can slide over each other. Rubber is flexible, waterproof and durable, properties that make it suitable for tyres.
