A2.0 Flashcards
where are the non-metals located on the periodic table?
to the right of the staircase line
what is a word used for unreactive?
inert
where are the metalloids located on the periodic table?
along the staircase line (there are 8 of them)
why can hydrogen be both a metal or a non-metal?
because it is capable of both giving away and taking in electrons
what is group 1?
the alkali metals
very reactive
what is group 2?
the alkaline-earth metals
less reactive than group 1
what is group 17?
the halogens
react easily with alkali metals
what is group 18?
the noble gases
very unreactive
what is an isotope?
atoms of the same element that differ in the number of their neutrons
ex: carbon-12 and carbon-14 both have 6 protons but vary in their number of neutrons
what is an energy level?
regions around the nucleus
what is the octet rule?
the amount of electrons that each energy level can hold : 2-8-8
what is a Bohr diagram?
drawings to illustrate elements’ atomic structure
what is a valence electron?
valence electrons are all of the electrons on the outermost energy level
how is an ion formed?
ions are formed when atoms gain or lose electrons to become like the nearest noble gas
what is a cation?
a positively charged ion
what is an anion?
a negatively charged ion
what does IUPAC stand for?
International Union of Pure and Applied Chemists
what is an ionic compound?
composed of one metal and one non-metal
what is a molecular compound?
composed of two non-metals
what is a crystal lattice?
different shapes of crystals are formed by different ratios of cations to anions
what is a formula unit?
a formula unit is the ratio of cations to anions
naming ionic compounds
name the cation first (metal)
name the anion second (non-metal) and change the ending to “ide”
eg: K3N -> potassium nitride
what does aqueous mean? (aq)
dissolved in water
what is a subscript?
subscripts (small numbers written at the bottom) are when you need more than one of an ion to accommodate the electrons
what are multivalent metals?
elements that have more than one possible ion charge
what are polyatomic ions?
made up of several non-metallic atoms joined together, which have a charge as an entire group
the bond formed in a molecular compound is called..?
covalent bond
the bond formed in an ionic compound is called..?
an ionic bond
naming molecular compounds
name the first element
name the second and change the ending to “ide”
you need to use prefixes to tell you how many of each element
eg: SO2 -> sulfur dioxide
the prefixes for naming molecular compounds are..?
1 - mono 2 - di 3 - tri 4 - tetra 5 - penta 6 - hexa 7 - hepta 8 - octa 9 - nona (ennea) 10 - deca
molecular compounds with common names
water - H2O (l) glucose - C6H12O6 (s) sucrose - C12H22O11 (s) methane - CH4 (g) methanol - CH3OH (l) ethanol - C2H5OH (l) ammonia - NH3 (g) propane - C3H8 (g) hydrogen peroxide - H2O2 (l) hydrogen sulfide - H2S (g)
ionic properties
solid at room temperature high melting / boiling point form crystalline structures soluble in water conduct electricity in solution
why is water a polar molecule?
because it has a slightly negative and slightly positive pole
what is a solubility table?
used to determine whether or not an ionic compound is soluble by using a solubility table
(found in data booklet)
properties of molecular compounds
can be solid liquid or gas at room temperature.
their melting points are much lower than ionic compounds.
some form crystals but they are weak and do not hold their shape.
while some molecular compounds are soluble in water, their solutions will not conduct electricity
special properties of water
the 3D structure of ice crystals results from the unusually strong attraction between water particles, and means:
1) ice crystals and snowflakes are 6 sided
2) ice is less dense than liquid water - ice floats
what is a buffer?
buffers are compounds that keep the pH of a solution constant
what does pH stand for?
power of hydrogen
what is the pH of an acid?
lower than 7
what is the pH of a base?
higher than 7
what is the pH of a neutral substance?
7
properties of an acid
sour
wet
properties of a base
bitter
slippery
pH > 7
reaction with litmus : turns blue
naming acids
- ide ➡️ hydro___ic acid
- ate ➡️ ____ic acid
- ite ➡️ ____ous acid
what is neutralization?
when an acid and a base react together, their properties cancel each other out
the products of this reaction are water and a salt
what is a controlled substance?
chemicals classified as a controlled substance by the Canadian government based on :
their environmental effects
where are the metals located on the periodic table?
to the left of the staircase line
