Creation
What scientist developped an early periodic table?
Dmitri Mendeleev
Everything in our universe of made up of... ?
Atoms.
In the table, the columns are also called...
Groups.
Which element is in group 2 and period 3 of the periodic table?
Magnesium.
This class of elements are good conductors of heat and electric current.
Metals.
When did he publish his first periodic table of the elements?
In 1869.
What are atoms made up of?
They are made up of protons, neutrons and electrons.
In the table the rows are also called...
Periods.
How many electrons can the first shell hold? How many electrons can the second shell hold?
The first shell can hold a maximum of 2 electrons. The second shell a maximum of 8.
This class of elements are poor conductors of heat and electricity.
Non-metals
What did he do to make his classification work?
He left gaps to place elements not known at the time.
Where are electrons located?
Around the centre of the atom.
Where are valence electrons located?
In the outermost shell of the atom.
What do periods display?
How many shells an atom has.
As we go down the vertical columns (= the groups), the elements all have the same number of... ?
Electrons in their outer shell.
How could he predict the properties of undiscovered elements?
By looking at the chemical and physical properties of the elements next to a gap.
What is in the nucleus?
Protons and neutrons.
How many valance electrons do the elements in group 2 have?
2.
An atom of an element has the electronic structure 2,8,7. Which group of the periodic table is it in?
In group 7. The number of electrons in the outer shell of an atom gives the group number of the element.
What do you call the group of gases that are colourless, ordourless and very stable?
The noble gases.
Why do the elements show periodic trends?
Because of the similar electron configurations of the elements.
What does the atomic number display?
The number of protons in the nucleus
Why is each box colour-coded?
To show if the element is a metal or non-metal.
An atom of an element has the electronic structure 2,8,8,2. What is its atomic number?
20. (2 + 8 + 8 + 2 = 20). In a neutral atom, the atomic number is the same as the number of electrons.
What is the electronic structure of an atom of the element whose atomic number is 13?
2,8,3