Atoms!Ya can’t trust them, they make up everything!
Matter• Matter is anything that has mass and takes up space!• We have many different types of matter: pure substances, and mixtures.
• Law of Conservation of Matter – Matter can be neither created nor destroyed, merely transformed.
Most basic chemical - Atoms• Atoms are the smallest particles to have chemical properties.
• There are smaller particles, but they do not have chemical properties
• Atoms are made up of smaller particles called protons, neutrons, and electrons
• Different numbers of protons, neutrons and electrons determine an atom’s properties
Subatomic Particles
• Protons, Neutrons, and Electrons are called subatomic particles
because they are what make up atoms.
“Sub” meaning “within” or “beneath” the atom
Subatomic particles• Protons are:
• POSITIVELY CHARGED like the south end of a magnet
• BIG and GIVE the atom MASS
• They do not move within the atom
• They give the element its identity
• Neutrons are:
• NEUTRAL/HAVE NO CHARGE
• BIG and GIVE the atom MASS
• They do not move within the atom
• Stabilize the protons
Make up an atom’s nucleus
Subatomic particles (continued)• Electrons are:
• NEGATIVELY CHARGED like the north end of the magnet
• SMALL and DO NOT give the atom MASS
• Move rapidly around the nucleus
• Their movement is responsible for chemical reactions
Make up an atom’s electron cloud
Each atom has a nucleus made up of protons and neutrons
Each element has a unique number of protons
Properties of an atom
• Atomic number: the number of protons; it tells us which element the atom is for.
• Mass number: the number of protons plus the number of neutrons; how much the atom weighs.
• Charge: the positive charges plus the negative charges; if it is neutral, the number of protons is equal to the number of electrons
Atoms and Subatomic Particles• If an atom is neutral, the # of electrons equals the atomic number
• IF NEUTRAL: # electrons = # protons • If you are given an atom’s atomic mass #, you can calculate the
number of neutrons by subtracting the number of protons from this atomic mass #
• Mass # - Atomic # = # of Neutrons• If you have the # of neutrons you can add them to the # of protons
to discover the mass number• Atomic # + # of Neutrons = Mass #
Pure substances - Atoms• Pure substances contain only one type of particle (a unit of chemistry),
whether they are atoms or compounds
There are different types of atoms called elements.
• Each element has a different number of protons
• Each element has different characteristics from one another, especially associated with their class
Ions/ Isotopes
•Ions – atoms that have charge due to losing/gaining electron(s).
•Example: Na – electron = Na +1•Example: F + electron = Na -1
*Isotopes – atoms of the same element that have a different # of neutrons & mass.
12C6 = 6 protons & 6 neutrons vs. 13C6 = 6 protons & 7 neutrons
Periodic table
• Our periodic table directly tells us:
• The atomic number (how many protons)
• The average atomic mass (an average of all the atoms of that element)
• The symbol of the element
• The name of the element
Periodic Table
• Our periodic table tells us whether an element is a :
• a metal (to the left of the staircase)
• metalloid (touching the stair case)
• non-metal (to the right of the stair case)
• noble gas (the last column on the right)
**(These are classes of elements)
Metals
Metalloids
Non-metals
Noble gases
Pure Substances - Compounds
• When elements chemically bond together, they form a NEW UNIT of matter called a compound
• Compounds have different properties from the elements that make them up• Example, both hydrogen and oxygen support flame, yet, H2O (Water) puts out
flames!
Mixtures – a substance that contains 2 or more units of chemistry• Homogeneous –mixtures that are evenly distributed, even on the
atomic/molecular level
• Heterogeneous – mixtures that are not evenly distributed 100%, especially not on the atomic/molecular level.
