Tpoic 3 Atomic Structure Flashcards
What was daltons idea of an atom?
Solid spheres. Each atom of the same element was the same size, but different elements were different
How has daltons idea of an atom changed over time?
-Discovery of - electrons in 1897, people thought they were stuck on the outsize of the + sphere
-1909 atoms have a nucleus with a + charge and - electrons floating around it
-1913 energy levels/shells in which electrons orbit the nucleus
-1918 protons in the nucleus
1932 neutrons in the nucleus
How are atoms of different elements different?
Different elements have a different number of protons
What is the relative charge and relative mass of a proton, neutron and electron
Sub atomic atom Relative mass Relative charge
Electron 1/1835 -1
Proton 1 +1
Neutron 1 0
Why do all atoms have no charge
They have the same number of electrons and protons, the charge of which cancel out
How big is a nucleus compared to its atom?
The nucleus is 100,000 times smaller than the atom
Where is most of the mass in an atom found?
In the nucleus
What is the meaning of the atomic number?
The number of protons in an atom
What is the meaning of the mass number?
The number of protons + neutrons in an atom
How do you figure out the number of electron in an atom from the periodic table?
It is the same as the atomic number
What is an isotope?
An atom of the same type of element, but with a different number of neutrons
Why is the RAM of an element on the periodic table not a whole number?
It uses an average of all isotopes and how frequently they are found
