3.1.1.1 Atomic Structure Flashcards
What is the relative mass of an electron?
1/1840
What is the tiny particles theory?
Everything is made of many different atoms, which themselves are physically indivisible
Democritus 400BC
What is the Billiard Ball Model?
Atoms are the tiny indivisible particles of elements. The atoms each have their own characteristic mass. In chemical reactions, the atoms are rearranged
Experiments showed that elements could not be broken down into anything simpler
Calculations of atomic masses were undergone
John Dalton 1808
What is the Plum Pudding model?
Atoms are not divisible but made from positive and negative matter. Negative electrons are embedded in a positive matrix
Negative particles were emitted from the neutral atoms of a cathode
Negative particles had negative charge and very little mass
John Joseph Thompson 1897
What is the planetary model?
Atoms have a very small nucleus with negative electrons orbiting it
Rutherford experiment proved this
Ernest Rutherford 1911
What is the Quantized Shell model?
Electrons exist in shells of fixed energy around the nucleus
Atoms absorb and emit electromagnetic radiation which is a result of electron movement
Niels Bohr 1913
What is the structure in the nucleus theory?
The nucleus is composed of positively charged protons and neutral neutrons which have equal mass
Atomic number of an atom is equal to the number of positive charges but not it’s mass
Ernest Rutherford and James Chadwick 1935
What is the quantum model?
Orbital are regions where an electron is most likely to exist. Electrons can be considered to be waves. Electrons form new bonding orbital when atoms react with each other
Erwin Schrodinger 1922
What is charge density?
Charge on ion / ionic radius
Which of 3d and 4s is filled first in electronic configurations?
3d because it is more stable
What is the structure of the atom?
Protons and neutrons make up the nucleus Protons have a positive charge Neutrons have no charge Electrons orbit the nucleus in energy levels Electrons have a negative charge
What is group 1 in an atom?
The energy level furthest from the nucleus
