ATOMS AND PERIODIC TABLE Flashcards
Explain why atoms have an overall neutral charge
Protons are positive and electrons are negative
Atoms have equal numbers of protons and electrons
So the charges sum to zero
Describe at least 2 features of the Bohr model of the atom
Electrons orbit the nucleus at specific distances
Atoms have a positive nucleus
Mass is concentrated in the nucleus
Atoms are mostly empty space
Explain why Mendeleev left gaps in the periodic table
For undiscovered elements
State the relative charges of the 3 subatomic particles
Proton = +1
Neutron = 0
Electron = -1
State the overall charge of an atom
0
Describe the information about the electronic structure provided by an element’s period in the periodic table
How many shells an atom has
Name 2 characteristics of atoms proved by the gold foil experiment
The mass of an atom is concentrated in the nucleus
The nucleus has a positive charge
Give 2 ways in which elements are ordered in the modern periodic table
First by their atomic number, then in groups based on their properties
Give the word for the percentage of atoms in a sample that are a particular isotope
Abundance
Electronic configuration of sulfur
2.8.6
State the relative masses of the 3 subatomic particles
Proton = 1
Neutron = 1
Electron = very small p
In the modern atomic model, name the subatomic particles found in the nucleus
Protons and neutrons
Name the 4 main historical models of the atom in chronological order
Dalton, Plum Pudding, Nuclear , Bohr
Before Mendeleev, explain how scientists ordered the elements
By their Atomic weights
Explain why Mendeleev’s periodic table was eventually accepted by other scientists
Elements were discovered which filled the gaps and matched the properties he predicted
Describe the difference between mass number and relative atomic mass
Mass number is the number of protons and neutrons in one atom
Relative atomic mass is an average value that takes account of isotopes
Define isotopes
Atoms of the same element with different numbers of neutrons
Diagrams
Diagrams on iPad
