The Periodic Table Flashcards
What order did scientists arrange elements in the early periodic table? (1)
By atomic weight.
What is one difference between Mendeleev’s Periodic Table and the modern Periodic Table?
Elements are arranged in increasing atomic number instead of atomic mass.
How did Mendeleev develop the modern Periodic Table?
The elements are arranged in order of ______________________.
The horizontal rows are called _________.
The vertical columns are called _________.
Elements in the same group are __________ to each other
increasing atomic mass
periods
groups
similar
Why did Mendeleev’s periodic table become more widely accepted than previous
versions?
Because Mendeleev ___________ the ___________ of missing elements and ___________.
Elements that ___________ Mendeleev’s predictions were __________________________.
predicted
properties
left gaps
matched
discovered and filled the gaps
Give 2 ways Mendeleev overcame the problem of elements being placed in the wrong group:
Left gaps.
Changed order based on atomic weights.
Explain why the boiling points in the table (of fluorine, chlorine and bromine) are low: (2)
They have weak intermolecular forces.
So little energy is needed to overcome the intermolecular forces.
Explain the trend in the boiling points in the table (of fluorine, chlorine and bromine): (3)
The molecules get _________ down the group.
So the ________ between the molecules will ___________.
So _____________________ as you go down the group.
larger
forces
increase
boiling points increase
As you go down the table of Group 7 elements, reactivity ______________.
decreases
How does fluorine react with hydrogen compared to iodine?
(Even in cold conditions).
Fluorine reacts much faster and explodes.
What is the chemical test for chlorine and what is the result?
Placing damp litmus paper in chlorine.
It will be bleached white.
Why is it that when you go down the Group 1 Table elements become more reactive?
Further down Group 1 shells are __________________, therefore the electrons are _____ more easily.
further from the nucleus
lost
Explain why sodium is less reactive than sodium? (4 points)
Sodium has ____________________,
less ____________________,
________________ from the nucleus,
so it is _____________ to gain electrons.
fewer shells of electrons
electron shielding
stronger attraction
harder
How does lithium react with water?
It floats slowly around the surface of the water
and produces bubbles.
How does sodium react with water compared to lithium?
It floats around faster on the surface of the water.
Produces bubbles more quickly.
What are 4 properties of non-metals?
Poor conductors of heat and electricity.
Low melting/boiling points.
Dull in their appearance.
Weak and brittle.
