Revision Flashcards
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
