Chemistry EXAM

• The movement of particles from high concentration to low concentration, down a concentration gradient.

  Diffusion
• it requires no energy, it is passive.

  Diffusion
• solid particles can’t move because they are fixed. So they can’t diffuse
• Liquid and Gas particles can freely move, so they can diffuse.
• to get a solid to diffuse, you must?

  dissolve it
• what are the factors affecting diffusion?

  state of matter, temperature, size of particle and concentration gradient
• Diffusion happens quicker in gases than solids because the particles have more kinetic energy
• the higher the temperature, particles will have more kinetic energy and move quicker
• bigger particles takes longer to diffuse because it is heavier
• Mass in a given space

  Density
• It is a type of concentration

  Density
• Higer Density = Heavier
• Lower Density = Lighter
• Which state of matter has the highest density?

  Solids
• Which state of matter has the lowest density?

  Gas
• Smallest unit of matter that retains the identity of a substance

  Atom
• Describes an object or a system. Scientists uses this to explain things that happen, or to make predictions

  Scientific Model
• Atoms of the same element that have different number of neutrons

  Isotopes
• Protons and neutrons are called?

  nucleaons
• Protons and neutrons in an atom is its?

  Nucleon number or Mass number
• What are the 3 types of sub-atomic particles

  Protons, Neutrons and Electrons
• Protons and neutrons make up the?

  Nucleaus
• Center of the atom. Contains the mass of an atom

  Nucleaus
• Region that surrounds the nucleaus that contains most of the space in an atom

  Electron Cloud
• Good conductors of heat/energy

  Metals
• Solids at room temperature and is ductile and malleable

  Metals
• Majority of elements and vary in reactivity

  Metals
• poor conductors (britle) and vary in reactivity.

  Non-Metals
• Bridge between sides of table

  Transition Metals
• gases at room temperature

  Non-Metals
• Properties of metals and nonmetals and has variable conductivity

  Metalloids
• horizontal rows of elements and has an increasing atomic number

  Periods
• elements in the same vertical columns and have similar chemical properties

  Groups or Families
• arranged by the number of electrons in the

  outermost energy level

  valence electrons
• Very reactive especially to water and is usually stored in oil and argon to protect them from violent reactions

  Akali Metals
• Metals with a single valence electron and only found in nature as compounds

  Akali Metals
• 2 valence electrons

  Harder than metals in Group 1

  Variable reactivity with water

  Akaline Earth Metals
• Varying number of valence electrons

  All metals

  Varying reactivity

  Transition Metals
• Group 7A

  7 valence electrons

  Halogens
• 8 valence electrons

  Outermost energy level considered “full”, so they do not react

  Used to help other things remain unreactive.

  Noble Gases