Elements, Compounds, Molecules and Atoms
- A substance made from one type of atom only
- Elements are made up from atoms
- The only magnetic ones are: iron, cobalt and steel
- Two ore more atoms that are chemically joined together
- A molecule that contains more than one element
- Iron is an element and Sulphur is an element. When they are heated, a chemical reaction occurs and Iron Sulphide is formed and this is a compound
- All elements are made from atoms
Used to seperate an insoluble solid from a liquid
Used to separate a soluble solid from a liquid in order to collect the solid
Used to separate a liquid from any solid which is dissolved in it
Used to separate small amounts of two or more solids which are soluble in a particualr liquid
Made when a river carries pieces of broken rock and where the river meets the sea the rock is normally deposited into a pile which surns into stone
Examples of the rock: Sandstone and Limestone
Earth movement can cause rock to be squeezed. This means they are heated and put under pressure. The minerals contained change chemically forming metamorphic rocks.
Examples of the rock: Slate, Marble
The inside of the Earth is Hot. Molten (liquid) rock forms when rocks melt. The molten rock is called magma. When the magma cools and solidifies, igneous rocks form. Examples of the rock: Basalt, Granite
Most reactive to least reactive:
Potassium (please) Copper (Coachella)
Sodium (stop) Silver (singing)
Calcium (calling) Gold (Group)
Difference between mass and weight:
Mass: A measurement of matter in an object
Weight: A measurement of how hard gravity is acting on you at that moment
The forces acting on a car:
Speed= distance/time triangle: Pressure= force/area triangle:
Moment = force x distance from pivot
Reflection of light
A line/ray intersecting a given line or surface at right angles
Angle of incidence:
The angle between the ray of light that hits the mirror and the normal
Angle of reflection:
The angle between the normal and the ray of light that is reflected off of the mirror
The bending of light as it passes from one substance to another. if it goes from glass to air, the bending is caused by the difference in density between the two substances
When light hits a plae surface and changes direction
Light: energy given out by hot object
Kinetic: the object has energy because it's moving
Thermal: the heat energy contained in any warm object
Gravitational potential: the higher up, the greater its energy
Elastic potential: energy stored due to stretchinh an object
Chemical: energy in any food or fuel which is released when we respire
Electrical: most convenient, nearly all appliances need it to work
Sound: energy created by any vibrating object
( pitch= how close together, sound= how tall or small)
Heat energy is transferred by:
transfer of heat energy through a substance without movement of the substance itself, hotter to cooler
transfer of heat energy through the movement of particles themselves, hotter to cooler
Transfer of heat by waves, doesn't need particles
Transfer of heat energy due to the loss of particles from the surface of a liquid
Protein- growth and repair (fish,eggs,meat)
Carbohydrates- energy (potatoes, bread)
Fats- stored energy and heat insulation (milk, cheese, meat)
Vitamins- Cell chemistry (fresh veg, citrus fruits)
Minerals- healthy blood (iron), bones and teeth (calcium) (iron from brown rice, nuts/seeds,calcium from milk and cheese)
Fibre- Prevents constipation abd bowel cancer (veg, fruit, Weetabix)
Water- to replace water which is lost
Large starch, protein and fat molecules are broken down by enzymes
Respiration- is a combination of chemical reactions which release energy inside living cells
Aerrobic respiration- the release of energy from the breakdown of glucose by combining it with oxygen inside living cells.
Glucose + oxygen = carbon dioxide + water + energy
Anaerobic respiration-is a type of respiration that doesn't use oxygen. It is used when there is not enough oxygen for aerobic respiration.
glucose → lactic acid (+ energy released)
Carbohydrates supply glucose and other sugars that are converted into glucose
Female sex cells
Ovaries: contain hundreds of undeveloped eggs (ova)
Oviduct: What the ovary is connected to the uterus by. Lined with cilia- cilia waft egg into uterus
Uterus: (womb) muscular bag and where baby develops until birth
Cervix: The cervix is a ring of muscle at the lower end of the uterus. It keeps the baby in place while the woman is pregnant.
Vagina: The ****** is a muscular tube that leads from the cervix to the outside of the woman's body.
Male sex cells
The urethra is the tube inside the penis that can carry urine or *****. A ring of muscle makes sure that there is no chance of urine and ***** getting mixed up.
Testes:The two testes are contained in a bag of skin called the scrotum. They have two functions:to produce millions of male sex cells called sperm, to make male sex hormones, which affect the way a man's body develops.
Sperm duct and glands: The sperm pass through the sperm ducts, and mix with fluids produced by the glands. The fluids provide the sperm cells with nutrients. The mixture of sperm and fluids is called *****.
The penis has two functions:to pass urine out of the man's body, to pass ***** into the ****** of a woman during sexual intercourse.
- Air is warmed, moistened and filtered as it travels through the mouth and nasal passages.
- It then passes through the trachea and one of the two bronchi into one of the lungs.
- After passing into the many bronchioles, it finally arrives into some of the millions of tiny sacs called alveoli.
- This is where gas exchange takes place - oxygen passes out of the air into the blood, and carbon dioxide passes out of the blood into the air in the alveoli.
- Muscles contract, expanding ribs
- Diaphragm contracts to increase volume of the chest
- Air sucked into lungs
- muscles relax, ribs drop in and down
- Diaphragm relaxes, moving upwards
Photosynthesis- how it works
- Green plants absorb light energy using chlorophyll in their leaves
- Use it to react carbon dioxide with water to make glucose
- Glucose is used in respiration or converted to starch and stored.
- oxygen is produced as a by-product
Carbon dioxide + water + energy= glucose and oxygen
Not all glucose is turned into insoluble starch because some is needed for respiration
The most important elements for plants to stay alive are:
Plants get hydrogen and oxygen from water in the soil, and carbon and oxygen from carbon dioxide and oxygen in the atmosphere.
Electric current doesn't get used up in a circuit
Series circuit Parrallel circuit
Difference between a cell and a battery:
A cell is a single unit at the base voltage. A battery can be a single cell or multiple cells connected together in series or parallel to make the voltage/current rating desired.