Periodic Table Flashcards
What is the law octaves and who proposed the idea?
When elements were ordered in RAM,
it was noticed that every 8th starting from a given one
is kind of a reputation of the first
However the pattern broke for heavier elements because he left no gaps for undiscovered elements
This idea was proposed by John Newlands
How did Dimitri Mendeleev contribution to periodic table?
He also arranged the elements by atomic mass
But instead left gaps for undiscovered elements
and even predicted their atomic mass, properties of such metals like gallium
Compare and contrast Mendeleev’s table vs the modern periodic table?
Mendeleev’s is arranged in atomic mass while modern is arranged in atomic number
Transition metals and noble gases did not exist in Mendeleev’s table while the do in the modern periodic table
A group is a…
Vertical column
A period is a…
Horizontal row
Group 1 metals are called
Alkali metals
Group 2 metals are called…
Alkaline earth matals
Group 7 metals are called…
Halogens
Group 8/0 metals are called…
Noble gases
In halogens what are the colour and state of following elements:
Fluorine-
Chlorine-
Bromine-
Iodine-
Fluorine- pale yellow gas
Chlorine- pale green gas
Bromine- red brown liquid
Iodine- dark grey solid
The reactivity of a metal depends on…
The tendency to lose it’s outer shell electron(s) and form it’s positive ion
Why do melting points decrease down group 1?
The metallic bonds decrease down group 1 as there is a an increasing number of shells
Which causes the delocalised electron to be further from the nucleus.
This then causes melting points to decrease
Why does the reactivity of metals increase down group 1?
The reactivity of group 1 metals depends on the tendency to lose it’s outer shell electron and form it’s positive ion.
The tendency to lose outer shell electron increases down group 1 as the outer shell electron is further away from the nucleus as there are more shell.
The attractive force decreases and and the metals become more reactive
Why are group 1 metals stored in oil?
To stop it reacting with moisture and air
Why do boiling points and melting points increase down group 7?
As the molecules get bigger the Van Der Waals forces increases and get harder to break
