End of year revision topic 1 Flashcards
How are compounds formed?
Formed from elements by chemical reaction
What do compounds contain?
Two or more elements chemically combined in fixed proportions
How are compounds separated?
Can only be separated into elements by chemical reactions
Chemical symbols
For a compound, chemical symbols of the atoms it contains are combined to give its formula for example, carbon monoxide is CO, meaning each molecule of carbon monoxide has one carbon atom joined to one oxygen atom
What is the word and symbol equation for calcium chloride?
Calcium + chlorine
Ca + Cl2
What is the word and symbol equation for sodium sulfide?
Sodium + Sulfur
2Na + S
Describe the process of chromatography
- Draw a pencil line near bottom of filter paper
- Add spot of ink to line and place sheet in beaker of solvent, make sure ink isn’t touching solvent
- place lid on top of container to stop solvent evaporating
What can simple distillation be used for?
Separating out a liquid from a solution
What does the plum pudding model suggest?
That the atom is a ball of positive charge with negative electrons embedded in it
What did Niels Bohr suggest?
Adapted the nuclear model by suggesting that electrons orbit the nucleus at specific distances
How did the scattering experiment lead to a change in the atomic model
The mass of an atom was concentrated at the centre and that the nucleus was charged
Describe the difference between the plum pudding model of the atom and the nuclear model?
Plum pudding models the protons and electrons in an atom and gives evidence of different charges in an atom
Nuclear proved that subatomic particles were placed in different places in the atom
How can we use the nuclear model to describe atoms
Describes the atom as having a positively charged nucleus with electrons orbiting it
