Science- Grade10 Chemistry Notes
Periodic Table: * Mass Number = protons + neutrons in the nucleus * Atomic Number = number of protons in the nucleus * Number of neutrons = mass number – atomic number
Example: Lithium (Li) * # of protons + # of neutrons = mass # * 3 + 4 = 6.9/ 7 * The atomic mass is the mean of all the isotopes of Lithium in nature; round the number
* Isotopes of a specific element have a varying number of neutrons * The number of neutrons do not affect the chemistry because they are not electrically active; neutral * Mendeleev organized the elements according to their atomic mass but today we organized them according to their atomic number * Staircase line separates the metals from the non-metals * Metals are shiny, conductive, malleable, react with acid solid * Non-metals are dull, brittle, insulators, don’t react with acid solid, liquid, or gas * Period: A set of repeating behaviours- same number of valence electrons * Group: A set of similar behaviours- same number of electron shells * Alkali Metals = first column * Alkaline Earth Metals = second column * Halogens = second last column * Noble Gases = last column * For metals; increasing reactivity to the left and downwards * For non-metals; increasing activity to the right and upwards
Atomic Structure: * Orbit 1 = 2 Electrons max. * Orbit 2 = 8 Electrons max. * Orbit 3 = 8 Electrons max. * Must fill inner orbits before moving to next level * The electrons in the outer most energy orbit are called valence electrons * Valance shell contains the valence electrons
Ion: * An ion is simply a regular atom that is charged * It gets charged when electrons are gained or loss * During a reaction, atoms prefer to look like their closest Noble Gas atom in their valence shell * The ionic charge is the charge of the atom with a full valence shell
Ionic
Example: Lithium (Li) * # of protons + # of neutrons = mass # * 3 + 4 = 6.9/ 7 * The atomic mass is the mean of all the isotopes of Lithium in nature; round the number
* Isotopes of a specific element have a varying number of neutrons * The number of neutrons do not affect the chemistry because they are not electrically active; neutral * Mendeleev organized the elements according to their atomic mass but today we organized them according to their atomic number * Staircase line separates the metals from the non-metals * Metals are shiny, conductive, malleable, react with acid solid * Non-metals are dull, brittle, insulators, don’t react with acid solid, liquid, or gas * Period: A set of repeating behaviours- same number of valence electrons * Group: A set of similar behaviours- same number of electron shells * Alkali Metals = first column * Alkaline Earth Metals = second column * Halogens = second last column * Noble Gases = last column * For metals; increasing reactivity to the left and downwards * For non-metals; increasing activity to the right and upwards
Atomic Structure: * Orbit 1 = 2 Electrons max. * Orbit 2 = 8 Electrons max. * Orbit 3 = 8 Electrons max. * Must fill inner orbits before moving to next level * The electrons in the outer most energy orbit are called valence electrons * Valance shell contains the valence electrons
Ion: * An ion is simply a regular atom that is charged * It gets charged when electrons are gained or loss * During a reaction, atoms prefer to look like their closest Noble Gas atom in their valence shell * The ionic charge is the charge of the atom with a full valence shell
Ionic