| what is diffusion | Diffusion is the movement of a substance from an area of high concentration to an area of low concentration. |
| is the movement of particles in diffusion random | yes |
| what is an example of diffusion | osmosis |
| why can insects walk on water | it has a high surface tension |
| what are the three states of matter | solid,liquid,gas |
| what are the particles like in a solid | they slightly vibrate in a fixed position and form an regular pattern but they cant move from place to place |
| what can't solids do | be poured or compressed |
| what are the particles like in a liquid | particles still touch their neighbors but they move around, sliding over each other randomly |
| what can't a liquid do | be compressed but it can be poured |
| what are the particles like in a gas | they can move quickly in all directions widely-spaced particles move around randomly and fill any given space |
| what force attracts particles together | bonds |
| why cant solids be compressed | the particles are too close together and have no space to move into |
| The bonds in a liquid are strong enough to keep the particles ---- | close together |
| The bonds in a liquid are weak enough to let the particles ---- | move around each other |
| why can't liquids be compressed | because the particles are close together and have no space to move into |
| what is the equation for neutralization | acid+alkaline=neutral substance + salt |
| what is an example of a neutral substance | water |
| what do all acids contain | hydrogen |
| when using the equation for neutralization to make the salt the ----- goes first then the ----- | alkali acid |
| turn nitric acid into a salt | nitrate |
| turn hydrochloric acid into a salt | chloride |
| turn sulfuric acid into salt | sulfate |
| what is the PH scale | It is an universal indicator which shows how acidic or alkaline a substance is by using colours |
| on the ph scale what are the main acidic numbers | 0-6 |
| on the ph scale what number is neutral | 7 |
| on the ph scale what are the main alkaline numbers | 8-14 |
| how can you tell if a substance is acidic or alkaline | universal indicator, red cabbage or litmus paper |
| what is the particle model | a scientific theory that explains the properties of solids, liquids and gases by suggesting that all matter is made of particles, and that those particles behave differently in solids, liquids and gases |
| are particles the same shape | no some can be long chains of atoms |
| different shaped particles can fit together in different ways which can change the properties of solids and liquids such as the strength or viscosity true or false | true |
| If particles collide with enough kinetic energy it can break the chemical bonds holding the atoms to each other in a molecule true or false | true |
| what happens to particles when the temperature increases | they gain more kinetic energy |
| what happens to the particles when the pressure is increased | they collide more often increasing the risk of the chemical bonds breaking and arranging into new compounds |
| when drawing atoms what is the maximum the first shell can have | 2 electrons |
| when drawing atoms what is the maximum the rest of the shells can have | the electrons can be drawn like this 2,8,8,2 8 electrons |
| on the periodic table what do the groups down and the periods show | how many electrons on the outer shell and number of electron shells |
| what does the number on the top and bottom of the element show | top= number of protons and neutrons bottom= number of protons |
| number of --------= number of electrons | protons |
| look | did u look |
| what is combustion | it means burning |
| what is a combustion reaction | in a combustion reaction a substance reacts with the oxygen and transfers energy from the surroundings as light and heat |
| what is a name for the oxygen compound | oxides |
| when does combustion happen | at high temperatures |
| why do you see a flame when things burn | energy is transferred as light and heat |
| what is methane | carbon and hydrogen atoms |
| what happens when methane reacts | hot blue or orange flame |
| what is the equation for methane combustion | methane + oxygen = carbon +water |
| what is in every combustion reation | oxygen |
| what is a compound | a compound is a substance that contains atoms of two or more different elements |
| what is the plural version or formula | formulae |
