half-term 1- diffusion, particle model, the atom, gas pressure Flashcards
solid
- particles are fixed
- cannot be compressed
- particles have little energy, does not move but vibrates
liquid
-particles flow and tale shape of container
cannot be compressed very much as particles are close
-particles have more energy so move
gas
- particles always fill container they are in
- can be compressed, because of space between particles
- particles have a lot of energy and move randomly very fast in all directions
diffusion definition
the movement of a substance from an area of high concentration to an area of low concentration.
In what does diffusion occur and why?
diffusion happens in liquids and gasses because their particles move randomly from place to place, will still occur if air is completely still.
what can prolong the time taken for something to diffuse?
collisions and changes take place and therefore it may take a while, all particle don’t diffuse at the same time.
what is at the top of an atom symbol and what is it?
mass number= number of protons + neutrons
what is at the bottom of an atom symbol and what is it?
atomic number= number of protons and electrons
what is the charge of a proton
+1
what is the charge of an electron
-1
what is the charge of a neutron
0
atomic number
- always the smaller number
- it tells you the number of protons in an atom’s nucleus
- the number of electrons and protons are the same in an atom
Atoms are the smallest part of ………. .
elements
All atoms in an element are ………. but atoms from different element are ……….. from one another.
identical
different
gases
- particles have more energy at higher temperature so diffusion is quicker
- gases diffuse quickly as particles are far apart and don’t bump into each other
- small particles diffuse quicker than big particles
