Atomic Structure Flashcards
What does the periodic table show and around how many elements are there?
All the elements that have been discovered; there are approximately 100.
What is an atom?
The smallest part of an element that can exist.
What is an element?
A substance made up of only one type of atom.
What is a compound?
Two or more different elements that are chemically combined in a fixed proportion.
How do you separate compounds?
With a chemical recaction
What is a mixture?
Two or more different elements or compounds not chemically combined
How do you separate mixtures?
Using physical processes
What are examples of processes that can separate mixtures? (5)
- Filtration
- Crystallisation
- Simple distillation
- Fractional distillation
- Chromatography
What is a molecule?
Two or more elements held together by a chemical bond (whether the same or different).
What is a miscible?
Liquids that dissolve in each other, mixing completely.
e.g., ethanol + water, lemonade, wine etc.
What is shown in a chemical equation?
- The reactants (what you start with).
- The products (the new substance).
What does it mean to have a balanced symbol equation?
There’s the same number of each atom on both sides of the equation.
What’s the law of conservation of mass?
Total mass of the products formed in a reaction is equal to that of the reactants.
What are the state symbols?
S, L, G, AQ
What does the state symbol ‘S’ stand for?
Solid
What does the state symbol ‘L’ stand for?
Liquid
What does the state symbol ‘G’ stand for?
Gas
What does the state symbol ‘AQ’ stand for?
Aqueous solution (substances dissolved in water)
What is filtration?
The physical process which separates insoluble solids from a solution/liquid.
What is the process of filtration?
- Put the solution into the filter paper, in the filter funnel
- The solvent passes through the tiny pores in the filter paper
- The insoluble particles remain on the filter paper, in the filter funnel, as a residue
What is crystallisation?
The physical process which separates soluble solids from a solution [liquid] using evaporation.
What is the process of crystallisation?
- Gently heat the solution to evaporate the solvent.
- Crystals will form in the evaporating dish.