(states of matter)

• CHEMICAL REACTIONS: What is an element?

  A substance containing only one type of atom.
• CHEMICAL REACTIONS: What are some examples of elements?

  (1) Mg

  (2) O(2)
• CHEMICAL REACTIONS: What do chemical reactions cause atoms to do?

  They cause atoms to change what they're bonded to.
• CHEMICAL REACTIONS: What is a compound?

  A substance containing two or more different types of atoms chemically bonded.
• CHEMICAL REACTIONS: What is the 'conservation of mass'?

  Atoms can neither be created or destroyed in a reaction, equations must be balanced.
• CHEMICAL REACTIONS: What do you call the chemicals on the left of a chemical equation?

  The reactants.
• CHEMICAL REACTIONS: What do you call the chemicals on the right of a chemical equation?

  The products.
• CHEMICAL REACTIONS: What chemicals always have to have a (2) next to them when written alone?

  (1) Oxygen; O(2)

  (2) Chlorine; Cl(2)

  (3) Nitrogen; N(2)
• CHEMICAL REACTIONS: How do you balance chemical equations?

  (1) count the amount of each chemical on each side.

  (2) do not change any little numbers, only change big numbers (ones in front of molecule)

  (3) trial and error to balance amount of each chemical on both sides

  (4) double check an recount each chemical to make sure its right.

  
• ATOMIC STRUCTURE: Who discovered the Atomic Theory?

  John Dalton.
• ATOMIC STRUCTURE: What was John Dalton's theory?

  Atomic Theory; matter is made of indivisible particles.
• ATOMIC STRUCTURE: Who created the 'Plum Pudding' model?

  J.J. Thomson.
• ATOMIC STRUCTURE: What is the 'Plum Pudding' model?

  The theory that the atom was a positive charge with many little negative electrons dotted around it:

  
• ATOMIC STRUCTURE: Who created the 'Nuclear' model?

  Ernest Rutherford.
• ATOMIC STRUCTURE: What is the 'Nuclear' model?

  The discovery that the nucleus was small, in the centre of an atom and positively charged by finding that most alpha particles went straight through a gold foil; very few deflected back.
• ATOMIC STRUCTURE: Who discovered electron shells?

  Niels Bohr.
• ATOMIC STRUCTURE: Who discovered neutrons?

  James Chadwick.
• ATOMIC STRUCTURE: All together, what are the five stages of the atomic model developed over time?

  (1) The atomic theory; theory of matter being made of indivisible particles-John Dalton.

  (2) The 'Plum Pudding' model; theory that atom was a positively charged sphere populated with electrons-JJ Thompson.

  (3) The 'Nuclear' model; discovery that nucleus was small, in the middle of an atom and positively charged (alpha particles)-Ernest Rutherford.

  (4) Electron shells-Neils Bohr.

  (5) Neutrons-James Chadwick.

  
• ATOMIC STRUCTURE: What relative charge does a proton have?

  Positive (+1)
• ATOMIC STRUCTURE: What relative charge does a neutron have?

  Neutral (0)
• ATOMIC STRUCTURE: What relative charge does an electron have?

  Negative (-1)
• ATOMIC STRUCTURE: What relative mass does a proton have?

  1
• ATOMIC STRUCTURE: What relative mass does a neutron have?

  1
• ATOMIC STRUCTURE: What relative mass does an electron have?

  almost 0 (very small)
• ATOMIC/MASS NUMBERS: What is an atom's 'mass number'?

  The number of protons and neutrons in a nucleus.
• ATOMIC MASS/NUMBERS: What is an atom's 'atomic number'?

  The number of protons in a nucleus.
• ATOMIC MASS/NUMBERS: What does the atomic number also show if it is an atom?

  The number of electrons (in order to be neutral)
• ATOMIC MASS/NUMBERS: What is an ion?

  A charged atom.
• ATOMIC MASS/NUMBERS: What must it mean if a molecule has a different number of protons and electrons?

  It is an ion rather than an atom.
• ATOMIC MASS/NUMBER: What does it mean if the mass number of an atom is not a whole number?

  It's mass number is an average mass of all isotopes.
• ATOMIC MASS/NUMBERS: What is relative abundance?

  Percentage of each isotope in a naturally occurring sample.
• ATOMIC MASS/NUMBERS: How do you workout the average mass between isotopes?

  Average mass = total mass of 100 atoms/100 = (isotope mass 1 x percentage abundancy)+(isotope mass 2 x percentage abundancy)
• Example: (chlorine 35+37)

  
• DEVELOPMENT OF THE PERIODIC TABLE: How were the elements in the periodic table initially ordered?

  According to their atomic 'weight' + also grouped together due to having similar properties.
• DEVELOPMENT OF THE PERIODIC TABLE: Who worked to rearrange the periodic table?

  Dmitri Mendeleev.
• DEVELOPMENT OF THE PERIODIC TABLE: How did Mendeleev rearrange the periodic table?

  He realized it made more sense to swap/reverse the order of some elements instead ordering them by atomic mass and leaving gaps for predicted elements that had not yet been discovered.
• DEVELOPMENT OF THE PERIODIC TABLE: How correct was mendeleev's table over time?

  It's proven largely correct and serves as the basis of the modern periodic table.
• DEVELOPMENT OF THE PERIODIC TABLE: Which elements did mendeleev leave gaps for?

  Gallium, Germanium, and Scandium.
• ELECTRONIC CONFIGURATION: What order do electrons fill up shells?

  2,8,8,2.
• ELECTRONIC CONFIGURATION: What kinds of metals are past calcium (Ca)?

  The transition metals.