Atomic Structure,isotopes, Compounds, Formula And Equations Flashcards
What is stated in daltons atomic theory
Atoms are tiny particles made of elements
Atoms can’t be divided
All atoms in an element are the same
Atoms of one element are different to those of other element
What did Thompson discover about electrons
They have a negative charge
They can be deflected by a magnet and electric field
They have very small mass
Explain the plum pudding model
Atoms are made up of electrons moving around in a sea of positive charge
What were Rutherfords proposal after the gold leaf experiment
Most of the mass and positive charge of the atom are in the nucleus
Electrons orbit the nucleus
Most of the volume is the space between the nucleus and the electrons
Overall positive and negative charges must balance
Explain the current model of the atom
Protons and neutrons are found in the nucleus
Electrons orbit in shells
Nucleus is tiny compared to the total volume of atom
Most of atoms mass in the nucleus
Most of the atom is empty space between the nucleus and the electrons
What does the atomic number tell about an element
Atomic number = number of protons in an atom
Which letter is used to represent the atomic number of an atom
Z
Which letter represents the mass number
A
How is mass number calculated
Mass number = number of protons + number of neutrons
How to calculate number of neutrons
Number of neutrons = mass number - atomic number
Define isotope
Atoms of the same element with different number of neutrons
Why does different isotopes of the same element react in the same way
Neutrons have no impact on the chemical reactivity
Reactions involve electrons, have the same number of electrons in the same arrangement
What are ions
Charged particles that is formed when an atom loses or gains electrons
Define relative atomic mass
The weighted mean mass of an atom of an element compared with one twelfth of the mass of an atom of carbon-12
What is the unit of relative atomic mass
No units
Define relative isotopic mass
The mass of an atom of an isotope compared with one twelfth of the mass of an atom of carbon-12
The relative isotopic mass is same as which number
Mass number
What two assumptions are made when calculating mass number
1- contribution of the electron is neglected
2- mass of both proton and neutron is taken as 1.0 u
How to calculate the relative molecular mass and relative formula mass
Both can be calculated by adding the relative atomic masses of each of the atom making up the molecule or the formula
What are the uses of mass spectrometry
- identify unknown compounds
-find relative abundance of each isotope of an element
-determine structural information
How does a mass spectrometer work
The sample is made into positive ions
They pass through the apparatus and are separated according to mass to charge ratio
A computer analyses the data and produces mass spectrum
How is the group number related to the number of electrons
Group number = number of electrons in the outer shell
Does the group number indicate horizontal or vertical column in the periodic
Vertical column
Do metals normally gain or lose electrons
Lose electrons
