Periodic table for SQA National 5 Chemistry
This page covers the following topics:
1. Periodic table structure
2. Electronic structure
There are specific names used for some groups of the periodic table:
group 0/8 (18) → noble gases
group 1 → alkali metals
group 7 (17) → halogens
Elements in the same group have similar properties since they have the same number of electrons in their outer shell. For groups 1-2 and 3-8 it is the same as the group number. For example, phosphorus has 5 electrons in its outer shell. If you use a periodic table with 1-18 group numbers, you should convert groups 13-18 to 3-8 respectively as the aforementioned rule doesn’t necessarily apply for the groups 3-12.
As you go down a group, the elements get bigger as they gain additional shells of electrons.
The electronic structure is the way in which electrons are arranged in an atom. Electrons in atom are arranged in shells (or energy levels) surrounding the nucleus. For many atoms, the electrons in an atom occupy the shell nearest the nucleus first, until it is full.
The first shell can contain 2 electrons. For elements up to and including calcium, the second and third shells can contain 8 electrons. Their electronic structure can be written as a numbers x, y, z, where x represents the number of electrons in the first shell, y in the second and z in the third.
Each electron shell corresponds to an energy level. For example, electrons that are in the second electron shell are in the second energy level.
What is the electronic structure of sodium which has 11 protons?
The electrons in an atom occupy the shell nearest the nucleus first, until it is full. The first shell can contain 2 electrons. For elements up to and including calcium, the second and third shells can contain 8 electrons.
Sodium has 11 electrons as it has 11 protons.
Allocating these 11 electrons into the first few electron shells gives 2, 8, 1.
2, 8, 1
Which element has the electronic structure shown in the picture?
Electronic structure 2, 8, 4 means that the element has 2 + 8 + 4 = 14 electrons.
The number of electrons and the atomic number match for atoms.
Thus, the atomic number of the element is 14 and it is silicon.
What is the name of group 1 of the periodic table?
Group 1 of the period table is called alkali metals.
What is the order electron shells fill up: lowest to highest, highest to lowest or in a different order?
Electron shells fill lowest energy levels first, then higher ones.
lowest to highest
Name 3 smallest halogens.
Since going down a group the atomic radius increases, we should pick the top 3 halogens; fluorine, chlorine, bromine.
fluorine, chlorine, bromine
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