An element can have the same number of protons but a different number of neutrons and still be the same element. This is called an isotope.
The atomic number is always equal to the number of protons an element has.
Despite what we may think, so long as the chemical formula of a substance stays the same, a physical change has occurred. If H2O(s) changes to H2O(aq), it is only a phase change. However, if we break down H2O into it’s components, then there has been a chemical change.
Classifying equations- we’ve done a worksheet. Many students say they have trouble with double replacement and single replacement. Can you help them work on this?
Ionic- forms between ions, a metal and a nonmetal, steals electrons
Metallic- forms between metals when the positive nuclei of other atoms pull the valence electrons slightly out of their orbital shell; sea of valence electrons
Covalent- forms between nonmetals, bonds are shared. There are three- single, double and triple.
Single bonds- share one pair (two) of valence electrons
Double bonds- share two pairs (four) of valence electrons
Triple bonds- share three pairs (six) of valence electrons
Students must be able to tell whether NaCl is an ionic compound or a covalent compound
Nucleus- center of the atom, contains protons and neutrons
Protons- positively charged particles in the nucleus
Neutrons- neutral particles in the nucleus
Electrons- particles that orbit around the nucleus, “cloud of electrons”- 2)8)8)
Malleable- being able to be hammered and bent; associated with metals
The periodic table is laid out by atomic mass. As we move across the periodic table, reactivity falls- with the most reactive elements on the left side (alkali metals) and the least reactive elements on the right side (noble gases.)
Steps for writing ionic bonds:
Write down elements with charges
Cross charges
Remove charge sign
Reduce
Remove ones
Steps for balancing equations:
Write equation
Draw boxes around chemical formula ONLY (no coefficient)
Count # of atoms on each side
Place appropriate coefficient in front of boxes so that when multiplied (distributed,) atoms equal each other
Rewrite equation w/ correct coefficients
Memorize Polyatomics:
NO4: Ammonium Charge: +1
NO3: Nitrate Charge: -1
HCO3: BiCarbonate Charge-1
CO3: Carbonate Charge: -2
SO4: Sulfate Charge: -2
PO4: Phosphate Charge: -3
Nucleus of an atom only contains protons and neutrons. Therefore, the nucleus is positively charged.
Ions form when atoms become charged, either negatively or positively.
The atomic number is always equal to the number of protons an element has.
Despite what we may think, so long as the chemical formula of a substance stays the same, a physical change has occurred. If H2O(s) changes to H2O(aq), it is only a phase change. However, if we break down H2O into it’s components, then there has been a chemical change.
Classifying equations- we’ve done a worksheet. Many students say they have trouble with double replacement and single replacement. Can you help them work on this?
Ionic- forms between ions, a metal and a nonmetal, steals electrons
Metallic- forms between metals when the positive nuclei of other atoms pull the valence electrons slightly out of their orbital shell; sea of valence electrons
Covalent- forms between nonmetals, bonds are shared. There are three- single, double and triple.
Single bonds- share one pair (two) of valence electrons
Double bonds- share two pairs (four) of valence electrons
Triple bonds- share three pairs (six) of valence electrons
Students must be able to tell whether NaCl is an ionic compound or a covalent compound
Nucleus- center of the atom, contains protons and neutrons
Protons- positively charged particles in the nucleus
Neutrons- neutral particles in the nucleus
Electrons- particles that orbit around the nucleus, “cloud of electrons”- 2)8)8)
Malleable- being able to be hammered and bent; associated with metals
The periodic table is laid out by atomic mass. As we move across the periodic table, reactivity falls- with the most reactive elements on the left side (alkali metals) and the least reactive elements on the right side (noble gases.)
Steps for writing ionic bonds:
Write down elements with charges
Cross charges
Remove charge sign
Reduce
Remove ones
Steps for balancing equations:
Write equation
Draw boxes around chemical formula ONLY (no coefficient)
Count # of atoms on each side
Place appropriate coefficient in front of boxes so that when multiplied (distributed,) atoms equal each other
Rewrite equation w/ correct coefficients
Memorize Polyatomics:
NO4: Ammonium Charge: +1
NO3: Nitrate Charge: -1
HCO3: BiCarbonate Charge-1
CO3: Carbonate Charge: -2
SO4: Sulfate Charge: -2
PO4: Phosphate Charge: -3
Nucleus of an atom only contains protons and neutrons. Therefore, the nucleus is positively charged.
Ions form when atoms become charged, either negatively or positively.