Chemical patterns Flashcards
What is constant about all the atoms of a specific element?
The number of protons (and therefore electrons unless ionised)
Who thought up the periodic table?
Mendeleev.
How is the periodic table organised?
Groups (vertical columns) and periods (horizontal rows)
Horizontal means?
This way ———————–
Vertical means?
Like a tree or a lamp post
How are the elements sorted in the periodic table?
Mendeleev used relative atomic masses, we use the proton number
All the elements in a group are?
Similar in their chemical reactions.
As you go down the periodic table the nuclei of the elements become?
Bigger and heavier
What did the fact not all elements had been discovered mean for Mendeleev’s periodic table?
There were gaps
Why were Dobreiner’s triads and Newlands’ octaves rejected?
Most elements did not fit their pattern.
How can data about physical properties in the periodic table be used?
To make predictions.
When elements are heated they produce…… flames?
coloured
What can the coloured light produced by heating an element be split into?
A spectrum that is unique to each element.
Name an element that was discovered using spectroscopy?
Helium, found on the sun before it was found on earth.
What is in the middle of an atom?
A small nucleus.
Where are the electrons in the atom?
Travelling around the outside in shells.
What is the charge on a proton?
+1
What is the mass of a proton?
1
What is the charge on a neutron?
0
What is the mass of a neutron?
1
What is the charge of an electron?
-1
What is the mass of an electron?
almost zero
Atoms must have the same number of?
Protons and electrons
How do you find the relative atomic mass?
Number of protons + number of electrons = relative atomic mass
How are electrons arranged in an atom?
In shells around the nucleus.
The shells have space for how many electrons (going out from the nucleus)?
2.8.8.18
What is the difference between electrons in different shells?
They have different energy levels.
Where would you find the electrons with the lowest energy?
Next to the nucleus
What do the elements in group 0 have that makes them inert?
Full electron shells.