Atomic Structure and the Periodic Table Flashcards
What determines the size of an atom?
Volume of electron’s orbits
What is radius of an atom?
0.1 nano meters
What is the charge of the nucleus and why?
Positive charge because protons
What does the nucleus contain?
Contains protons and neutrons
Where is almost the whole mass of atom is concentrated?
In nucleus
What is no. of protons equal to?
no. of electrons
What does the nuclear symbol of atom (i.e. what’s on the periodic table) tell you?
Its atomic number and mass number
What a mass number?
Total number of protons and neutrons in atom
What’s the atomic number?
Number of protons
How do find the no. of neutrons?
Mass Number − Atomic Number
What is the name given to substances that only contains atoms with same number of protons?
Elements
Define isotopes
Different forms of same element, which have same no. of protons, but different no. of neutrons
What is relative atomic mass?
Average mass of one atom of an element (including
isotopes)
How are elements laid out in the periodic table?
In order of increasing atomic (proton) number
Where are metals & non-metals on the periodic table?
Metals are on left and non-metals on right
What does the group number tell you?
Number of electrons in outer shell
Exception Group 0 which has Helium (2 electrons)
What do periods show you?
New period = another full shell of electrons
What does having one electron on the outer shell do to an atom?
Makes them very reactive and gives similar properties