Science : chromatography , body , moon

3 topics in one for end of term exam

Topic 1 : Chromatography

  • used to separate the substance in a mixture

  • different types but they all have 2 phases

  • a mobile phase - when molecules can move (always a liquid or a gas)

  • stationary phase - where molecules can’t move (can be a solid or a really thick liquid)

  • during chromatography experiment the substances in the sample constantly move between the mobile and stationary phase (an equilibrium is formed between the 2)

  • definition of equilibrium : equal balance between any powers, influences, etc.; equality of effect.

  • mobile phase moves through stationary phase and anything dissolved with the mobile phase is moved with it

  • how quickly a chemical moves depend on how it’s distributed between the two phase (whether it spends more time in the mobile phase or the stationary phase)

  • the chemical that spends more time in the mobile phase will move further through stationary phase

  • normally the components in the mixture will separate through the stationary phase

  • (the solute is the substance being dissolved and a solvent is what is dissolving it)

    - filtration - crystallisation - evaporation - distillation -

  • filtration separates insoluble solids from liquids

  • evaporation and crystallisation separates solubles from liquids

  • distillation is used to separate mixtures which contain liquid

    (soluble substances can be dissolved and insoluble can’t)

  • evaporation method - pour solution into evaporating dish and heat the solution till the solvent eventually evaporates . Eventually , crystals will start t form

  • crystallisation method - pour solution in evaporating dish and gently heat . Once some of solvent evaporates or when u start to see crystals , remove from heat and leave too cool . The salt will start to form crystals .

  • distillation method - you purify the water by heating it and turn in git into a vapour that is then condensed back into a liquid

  • ok fine so basically pour solution into filtered paper and the solvent will go through into the glass and the solute will b on the filtered paper

Topic 2 : body (muscles , skeletal structure etc..)

  • bones stop u from being shapeless

  • bone is a living tissue with blood supply

  • calcium and other materials make the bone strong and slightly flexible

  • an average adult human contains 206 bones

  • Human skeleton, front and rear view with explanations. Vector illustration of human skeleton. Didactic board of anatomy of human bony system. Illustration of skeletal system with labels. A diagram of the main parts of the skeletal system.

  • bones are hard and strong so they can protect vital organs like your skull protects your brain , your ribcage protects your heart and lungs and your backbone protects your spinal cord

  • bones support the body , protect vital organs , help the body move and make blood cells

  • joints are when 2 or more bones are joint together and most joints are flexible

  • hinge joints - to move backwards and forwards for example the knee and elbow

  • ball and socket joints - for movement in all direction for example the hip and shoulders

  • fixed joints - like the name don’t allow any movement for example the skull

  • if bones moved against each other they would rub and cause lots of pain and eventually the bone will wear away

  • to stop this from happening , the ends of the bones in a joint there is cartilage , a strong , smooth tissue and it is kept slippery by fluids in the joints

  • the two bones are held together by ligaments


  • muscles are a type of tissue and lots of muscles work together to cause movement

  • your heart is a muscle made of cardiac muscle tissue , the muscle pumps blood around the body

  • other muscles are found in your gut to help squeeze the food along

    types of muscles :

  • neck muscles - holds the head up and move it in all directions

  • biceps - bend the arm

  • triceps - straighten the arm

  • shoulder muscles - raise and lower the arms

  • abdominal muscles - moves the torso and helps with breathing

  • thigh muscles - moves the lower leg

  • shin muscles - helps move foot up and down and side to side

  • calf muscles - pull the heel up and point toes

  • to make you move muscles work by getting shorter - they contract

  • tendons join the muscles and bone

  • muscles can only pull and cant push , this means two muscles have to work together to at a joint

  • if u only had one muscle in your arm u may be able to bend your arm but not straighten it

  • at each joint a pair of muscles work together to cause movement , these are known as antagonistic muscles

  • when one muscle contracts the other muscle relax

    You can use newtons scale to measure the strength of many different muscles

    Topic 3 : moon

  • the moon takes 27 days and 7 hours to orbit the sun once


  • The Moon Phases names in the correct order showing the progression from new moon, through waxing moons, to full moon, then back down through waning moons, to new moon again in a cycle

  • half of the moon is lit up by the sun all the time but as the moon moves around the earth it looks different on earth

  • the changing shapes are called phases of the moon

  • when the moon is in position 1 you only see the side of the moon that is in the shadow

  • in position 5 the sun lights up the whole moon so you see the whole side of it

  • a lunar month is a period of time from one new moon to the next new moon

  • when the moon comes between the sun and the earth it creates a shadow on the earths surface

  • if you are standing in the umbra the moon completely blocks the light from the sun and you will see a total solar eclipse

  • if you are standing in the prenumbra where only part of the sun is blocked you will see a partial solar eclipse

  • a lunar eclipse is when the earth comes between the moon and the sun

  • the earth spins on its axis

  • the earth orbits the sun

  • it takes 365 days to orbit the sun

  • the sun rises in the east each morning and reaches its highest at noon and then sets in the west in the evening

  • the suns gravity pulls the planets to orbit around it