Atomic Structures Flashcards
What is the nucleus composed of?
Protons and neutrons.
At atom consists of a central____?
Nucleus
What are in orbit around the nuclear in energy levels called shell?
Electrons
Give the relative mass and charge of each particle.
Proton- RM=1 , RC= +1
Neutron- RM=1, RC=0
Electron- RM=almost 0, RC= -1
The number of electrons in an atom= the number of ________
Protons.
The mass of a number is?
Protons and neutrons
Give the electronic structure of Magnesium
Mass number - 24
Atomic number- 12
2,8,2
Electronic structure of Flourine
Mass number- 19
Atomic number-9
2,7
What is the overall charge on a boron atom and why? Is this true of all atoms?
0, because this always happens with all atoms as the no. of protons and electrons are the same.
Fill in:
The number of outer electrons is equal to the _______ _________.
Group number
What are isotopes?
Isotopes are atoms of the same element that have the same number of protons but a different number of neutrons.
What is the relative atomic mass?
The R.A.M of an element is the average mass of its atoms taking into account the different proportions of isotopes.
How do you work out the R.A.M?
(Mass number x %)for 1st isotope + (Mass number x %)for 2nd / 100
Why does an atom never have any charge overall?
Overall the atom has zero charge. This is because the number of positive protons is the same as the number of negative electrons. The charges cancel out and this is true for all atoms!
There are three isotopes of magnesium Mg-24 (79%) Mg-25 (11%) Mg-26 (10%) Calculate the R.A.M for magnesium
24.31
