Atoms, Elements, Compounds And Mixtures Flashcards
What is the radius of an atom
0.1 nanometers
How does the size of the nucleus compare to the size of the atom
About 1/10000 of the size
What is the releotive mass of an electron
Very small
What does an atom become when electrons are added or removed
Ion
What is a substance called that only contains one type of atom
Element
What does the atomic and mass nummber do
Atomic is proton nummber
Mass number is protons and neutrons
What are isotopes
Different forms of the same element with different nummber of neurons. So different mass nummber
What is the repetitive atomic mass of an element
An average mass talking into account the different masses of isotopes and how abundant each isotope is
What is the formula to calculate relative atomic mass
Sum of (isotope abundance x isotope mass nummber) / sum of abundance of all isotopes
How do metals and non metals react
Metal atom losses an electron to form positive ions and the non metal gains an electron to form negative ions. The opposing charges mean they are strongly attracted to each other. This is called ionic bonding.
What is a mixture
Made of separate substances wich are not chemically bonded together so can be separated by physical processes.
Name 5 ways to separate a mixture
Chromatography, filtration, evaporation, simple distillation, fractional distillation
Hiw does filtration work
Fold a piece of filter paper into a funnel and put it on a conical flask and put the liquid through
How does evaporation work
Port solution into evaporation dish and put it on a a tripod and gauze and place a bunsen burner underneath. As solution evaporated a solid will begin to form. Keep going until you have a dry solid
How does crystallization work
Heat solution gently over a bunsen burner. Some of the solvent will evaporate so you have a concentrated solution. Remove the dish from the heat and leave it to cool. Filter crystals from the solution and leave them in a warm place to dry
What is fractional distillation used for
Separating liquids with similar boiling points
How does fractional distillation work
Put liquid in conical flask and attach fractionating column
Put over a heat sourse at a low tempeeture, lowest BP will evaporate first and pass into the condenser and the pure liquid can be collected
Raise temp to evaporate the other liquids and collect separately keeping an eye onto the temperature
why do atoms react
to complete their outer shell
why dont noble gasses really react
they have complete outer shells
