1.3 The periodic table Flashcards
How are the elements listed and approximately how many are there?
They are listed in the periodic table and there are approximately 100
Elements can be classified into two groups based on their properties; what are these groups?
Metals and non-metals
Compare the properties of
metals and non-metals
Metals:
High melting/boiling point, high heat/electrical conductivity, high density, shiny, malleable, form basic oxides
Non-metals:
Low melting/boiling point, low heat/electrical conductivity, low density, dull, brittle, form acidic oxides
What is formed when a metal reacts with a
non-metal?
An ionic compound (made of positive and negative ions).
What is formed when a non-metal reacts with a
non-metal?
A molecular compound containing covalently bonded atoms.
Atoms share electrons, as opposed to transferring electrons between
each other (ionic compounds).
What are the columns of the periodic table called?
Groups
What are the rows of the periodic table called?
Periods
Are elements in the same group similar or different?
They may have similar chemical properties, as they have the same
number of outer shell electrons.
In terms of energy levels, what are
the differences between elements
of the same period?
They have the same number of energy levels
Electrons occupy particular energy
levels, with each electron in an atom at a particular energy level; which available energy level do electrons occupy?
The lowest available energy level
What are the elements of Group 0 known as?
The noble gases
What makes the periodic table periodic?
Similar properties of elements occur at regular intervals
Elements in the same group have the same number of electrons in their outer shell; what does this tell us about their
chemical properties?
They have similar chemical properties
In terms of shells, what is the
difference between elements
in the same period?
They have the same number of shells
What change in shell number is seen as you move down a group?
The number of shells increases
How were early periodic tables ordered?
By the order of their atomic masses
What discovery explained why the order of atomic masses was not always correct?
Isotopes
How did Mendeleev overcome problems when creating the periodic table?
By leaving gaps for undiscovered elements
How did Mendeleev order the elements of the periodic table?
By atomic mass and similar properties
What are the majority of elements?
Metals
What elements react to form positive ions?
Metals
What elements do not react to form positive ions?
Non-metals
What are elements in Group 1 known as?
The alkali metals
State three characteristics of
the alkali metals
-All have one
electron in their
outer shell
-Low density
-Stored in oil (to
prevent reactions
with oxygen or
water)
-Soft (can be cut
with a knife)
How do Group 1 elements react
with non-metals? Why are these
reactions similar for the different
Group 1 elements?
They form ionic compounds that are soluble white solids and form
colourless solutions
They all have one electron in their outer shell.
How do Group 1 elements react with water?
They release hydrogen and form hydroxides which dissolve to form
alkaline solutions.
They react vigorously with water, fizzing and moving around
on the surface.
How does the reactivity change moving down Group 1? Why?
Reactivity increases as the atoms get larger and the distance between
the nucleus and the outer electrons increases and thus attraction from the
nucleus decreases, allowing them to more easily lose electrons.
State five characteristics of
Group 7
-7 electrons in
outer shell
-Coloured vapours
-Diatomic
molecules
-Form ionic salts
with metals
-Form molecular
compounds with
non-metals
State the Group 7 elements and
their states of matter.
-Fluorine (F), F2
is a pale yellow
gas.
-Chlorine (Cl), Cl2
is a pale green gas.
-Bromine (Br) Br2 is
dark brown liquid
-Iodine (I), I2 is a
grey solid.
State three changes that
occur in Group 7 as you move down the group
-Higher relative
molecular mass
-Higher melting and
boiling point
-Less reactive – less
easily gain
electrons
A more reactive halogen displaces a less reactive
one from an aqueous solution of its salt; explain the trend in reactivity of halogens in these reactions
Reactivity decreases down the group. As we go down the group, the atoms get larger, so an incoming electron will be less tightly held by the attractive forces
from the nucleus. That’s why Cl2 displaces Br– and I–
Describe the properties of noble gases. Discuss the trend in boiling
point down the group.
Non-metals, gases, low boiling points, unreactive (full outer shell; they
don’t easily accept or lose electrons).
The boiling point increases down the group, as the atoms get heavier.
State the colours of flames observed when lithium, sodium, and potassium burn in oxygen
Crimson-red, Li
Yellow-orange, Na
Lilac, K
Compare the Group 1 metals and transition metals. (Triple)
The group 1 metals and transition metals are heat and electricity conductors.
They are shiny when polished and form ionic compounds with non metals.
The transition metals have higher densities and higher melting points than Group
1 metals. They are less reactive and harder than Group 1 metals.
State three common
characteristics of transition metals. (Triple)
-Ions with different
charges
-Coloured
compounds
-Catalytic properties
What is a catalyst?
A catalyst is a chemical substance that increases the rate of a chemical reaction.
It is not used up over the course of the reaction.
State the colours of flames observed when lithium, sodium, and potassium burn in oxygen
Crimson-red, Li
Yellow-orange, Na
Lilac, K
