Flashcards
Chemistry Topic 1
Cards in this deck (27)
- 1How big is the nucleus of an atom0.1 nm (1x10 -10m)
- 2What is in a nucleusProtons and neutrons
- 3Question TextAnswer Text
- 4Question TextAnswer Text
- 5Electrons move round in ....Shells
- 6True or false? There is the same number of protons as electronsTrue
- 7An ion is ....When the number of protons doesn’t equal the number of electrons
- 8Isotopes are....Elements with a different number of neutrons
- 9Relative atomic mass =Sum of (isotope abundance x isotope mass number) / sum of abundance’s of all the isotopes
- 10Compounds are...When 2 or more elements chemically bonded together
- 11A mixture is ...2 or more elements mixed together, without a chemical bond
- 12A physical method is ....A separation that doesn’t include chemical reactions
- 13The properties of a mixture are...A mixture of properties from each element
- 14Describe chromatography?-draw a pencil line near the bottom of the filter paper
-add a spot of ink on the line and place paper in a beaker of solvent
-don’t let the ink touch the solvent
-place a lid on beaker to stop evaporation
-solvent seeps up paper and the dye will separate up the paper at different rates
-leave paper to dry and assess - 15Filtration is used when..The product is an insoluble solid
- 16Evaporation method?-pour the solution into an evaporating dish
-slowly heat the solution
-the solvent will evaporate and start to form crystals
-keep heating the dish until dry crystals are formed - 17Crystallisation?-pour the solution into an evaporating dish and gently heat
-once solvent has evaporated crystals will start to form
-leave to cool
-salt should start to form because of the cold
-filter crystals out the solution and leave in a warm place to dry - 18Describe distillation?-the solution is heated
-the vapour is cooled, condensed then collected
-the rest of solution is left behind in the beaker - 19Describe fractional distillation?-put the mixture in the flask and place fractionating Column on top
-the different liquids have different boiling points
-the one with the lowest boiling point evaporates first and when the thermometer matches its boiling point, that liquid will reach the top of the column
-the liquids each gradually start doing the same but stop at different points - 20In early 1800s elements were arranged by ...Atomic mass
- 21Dmitri Mendeleev did what?In order of atomic mass, but switched some so it’s fit the similar properties but gaps were left for undiscovered elements
- 22Metals are elements that can form ...Positive ions
- 23Non-metals form ...Negative ions
- 24Metals have what properties?-strong but can be bent/hammered into different shapes
-delocalised electrons so can conduct heat and electricity
-high melting/boiling points - 25Non metals have what properties?-dull looking
-brittle and not all solids at room temp.
-don’t conduct electricity - 26Alkali metals (describe)-very reactive
-soft and low density
-increased reactivity as you go down
-low melting point - 27Describe group 7 elements?-less reactive as you go down
-high melting points as you go down