Definition of an atom
- The basic building block of everything
- smallest unit of matter that can be divided into electrically charged particles (protons, neutrons, electrons)
Subatomic particles of an atom
l. Proton - positive charge - slightly smaller than neutrons
2. Neutron- neutral charge - present in all nucleus except hydrogen H
Electron - negative charge - travels around nucleus - 1000 x smaller than proton
What makes up the atom nucleus?
Protons and neutrons
Electron shell orbit and corresponding # of electrons
1:2
2: 8
3: 18
4:32
Name of periodic table rows and columns
Periods and groups
What does the period # tell about elements
Of period = # of electron shells
What does the group # tell about the element
Group # = # of valance electrons not including forbidden zone
What does the atomic # tell?
of protons and electrons (same #)
What does atomic mass tell?
Of protons + neutrons
number of protons and neutrons
Define ionic bonding
- Atoms gain or lose valence electrons to become stable, often 8 valence electrons
- formation of charged ions
- positive = cation
- negative = anion
What charge do metal ions tend to have and why?
Positive (+)
- tend to lose electrons to become stable
- more protons (+ charge)
What charge do non-metal ions tend to have and why?
Negative charge
- closer to valence shell, therefore, gain electron (- charge)
Define covalent bonding
- Non-metals share valence electron pairs to become stable
Why do non-metals prefer to share electrons?
- High electronegativity
- strong tendency to attract electrons
Instead of losing ( requires more energy)
What does covalent bonding create?
Molecules of 2 or more atoms bonded together
Formula for ammonia
NH4-1
Nitrate formula
NO3-1
Cyanide formula
CN-1
Sulfate formula
SO4-2
Phosphate formula
PO4-3
Carbonate formula
CO3-2
Sulfuric acid formula
H2SO4
Hydroxide formula
OH-1
How does the distance of electrons impact the element’s reactivity?
The further electron shells are from the nucleus, the less attraction and the easier the electron is lost, therefore, more reactivity
