Atoms and Ions Flashcards
What are atoms composed of?
A nucleus surrounded by electrons. The nucleus is made up of protons and neutrons
What does the mass number represent?
Number of protons plus number of neutrons
What does the atomic number represent?
Number of protons (number of protons and electrons are the same)
Why is the number of electrons ignored?
Because they’re tiny
What is an isotope?
An atom of the same element with a different number of neutrons
What is the relative atomic mass?
The weighted average mass of all the isotopes of an element
What is the formula of relative atomic mass?
SUM(Isotope mass x isotope abundance) / 100
What is the relative mass and the relative charge of a proton?
1 and +1
What is the relative mass and the relative charge of an electron?
1/2000 and -1
What is the relative mass and the relative charge of a neutron?
1 and 0
What is an electron?
Negatively charged particles
Why are electrons important?
Because they take part in bonding
What does the number of electrons in the outer shell show?
Which group in the periodic table
What are group 8 elements in the periodic table?
Stable atoms, therefore very unreactive
Give an example of a diatomic molecule
Oxygen (O2)
Why do ions form?
To gain or lose the electrons they need to become stable
What happens when a metal bonds to a non metal?
Electrons are transferred from the metal atoms to the non metal atoms. The metal ions have an overall positive charge
What do ions have the same electronic structure as?
The nearest noble gas
Why do group 1 metals have a charge of +1?
Because they have one outer electron to lose
What is the ion for hydroxide?
OH-
What is the ion for nitrate?
NO3-
What is the ion for sulphate?
(SO4)2-
What is the ion for carbonate?
(CO3)2-
How is the formula for a compound worked out?
Total positive charge must equal the total negative charge.
Example: what is the formula of magnesium chloride?
MgCl2
