C1 Flashcards
What are isotopes
Different forms of the same element which have same number of protons but a different amount of neutrons
How is the periodic table arranged
In columns called groups
What are all atoms made out of
Nucleus and electrons orbiting around
What are reactants
Substances you start with
What are products
New substance made
What does (s) mean
Solids
What does (L) mean
Liquid
What does (g) mean
Gas
What does (aq) mean
Aquous solutions
What are the differences between compounds and mixtures
- compounds have a fixed composition, whereas mixtures dont
- chemical reactions must be used to seperate elements in a compound, whereas mixture can be seperated more easily
- chemical bonds in compounds, but mixtures dont
What is filtration
A technique to seperate substances that are insoluble in a particular solvent. Eg sand in water, salt ect
What is distillation
A solution is heated and boiled to evapourate the solvent. Vapour is given off then enters a condenser. Thisnis an outer glass tube with water flowing through it that acts as a cooling a jacket
Who had the early ideas of an atom
John dalton, he suggested that substances were made up of atoms that were tiny hard spheres.
Who had evidence for electrons in atoms
JJ Thomson, a tiny negatively charged patricle that was found to have a mass about 2000 times smaller than the lightest atom
Who had evidence for the nucleus
Geiger and Marsden, they were doing an experiment with radioactive particles . They were firing positively dense chagred particles called alpha patricles at the thinnest piece of gold. They thought that this laser would go through the gold foil. But the results changed it, some parts pf the laser reflected showing that there was a positive centre of the atom which is called the nucleus
