Ch.1: Atomic Structure Flashcards
What is an atom?
The smallest particle of matter that can take place in a chemical reaction
What is an element?
A substance that contains only one kind of atom
What are the masses & charges of subatomic particles?
Mass: Charge:
Proton: 1 +1
Neutron: 1 0,Nil,No Charge
Electron: 1/1840 -1
Define Proton Number
The number of protons in a nucleus of an atom
Define Nucleon Number
Total number of protons and neutrons present in the nucleus of an atom
Why is the atom neutral?
As it has equal number of positive protons and negative electrons
What is an isotope?
Atoms of the same: proton number/Atomic Number/number of protons and electrons
but different: mass number/neutron number
Why do isotopes have same chemical properties?
They have same electrons in outer shell
Same electronic structure
How is the periodic table arranged?
In order of increasing proton number/atomic number
What is the trend across periodic table?
Metallic Character decreases as you go from left to right
(Metals on the left) & (Non-Metals on the right)
What do we call elements with a full outer shell?
Noble Gases- in group 8
What property do they have because of the full outer shell?
They are inert/unreactive
Groups and Periods in periodic table each represent:
Group number: Number of electrons in outer shell
Period Number: Number of energy shells
Where are transition elements located on the periodic table?
They are the short columns at the center of periodic table
What are the physical properties of transition elements?
The 3H:
-Hard/Strong
-High Mp & bp
-High Density
