Structure of atoms and ions Flashcards
Where are electrons found?
On the shell
Where are neutrons found?
In the nucleus
Where are protons found?
In the nucleus
What is the relative charge of a proton?
+1
What is the relative charge of a neutron?
0
What is the relative charge of an electron?
-1
What is the relative mass of a neutron?
1
What is the relative mass of a proton?
1
What is the relative mass of an electron?
1/1836
In an atom, where is all the mass concentrated?
In the nucleus, because electrons have a far smaller mass compared to protons and neutrons
How do you calculate the mass number of an atom?
Add number of protons and neutrons together
What is the atomic number of an atom?
The number of protons, the number of electrons
How do you calculate the number of neutrons?
Mass Number (Protons + Neutrons) - Atomic Number (= Protons, = Electrons) = Neutrons
E.g. Phosphorus
31 (Mass Number) - 15 (Atomic Number) = 16 Neutrons
What is the maximum number of electrons that can be held on shell 1?
2 Electrons
What is the maximum number of electrons that can be held on shells 2 and onwards (for the first 20 elements)?
8 Electrons
What are ions? What do they carry?
Ions are formed when atoms, or groups of atoms, gain or lose electrons. They carry an electrical charge, either positive (Cation) or negative (Anion)
How do you determine the charge of an ion?
Number of protons - Number of electrons
For the first 20 elements, atoms lose or gain electrons so they achieve what configuration?
A noble gas configuration (Group 0/8)
How do you write an ionic compound?
Start by writing the two ions next to each other, first positive then negative. If the numbers in the charges are the same, the formula is written with no negatives or positives (Metal is always written first). If they are different, solve like balancing equations.
E.g.
Li¹⁺ Cl¹⁻ → LiCl
Na¹⁺ S²⁻ → Na₂S
Al³⁺ NO₃⁻ → AlNO
