Atoms
Atomic number: is the number of protons in its nucleus (number at the top)
Mass number: is the sum of protons PLUS neutrons in the nucleus
- number of protons = atomic number.
- number of electrons = atomic number.
- number of neutrons = mass number - atomic number.
Isotopes
• How do isotopes of the same element differ from each other?
An isotope is one of two or more forms of the same chemical element. Different isotopes of an element
have the same number of protons in the nucleus, giving them the same atomic number, but a different
number of neutrons giving each elemental isotope a different atomic weight.
Electronegativity
• What is the most electronegative atom on the periodic table?
Fluorine
• How does electronegativity affect electrons in a covalent bond?
The more strongly an atom attracts the electrons in its bonds, the larger its electronegativity. Electrons in
a polar covalent bond are shifted toward the more electronegative atom; thus, the more electronegative
atom is the one with the partial negative charge.
Ionic Bonds
• What is an ionic bond? How is it formed?
electrovalent bond, type of linkage formed from the electrostatic attraction between oppositely
charged ions in a chemical compound
- form between two or more atoms by the transfer of one or more electrons between atoms.
Electron transfer produces negative ions called anions and positive ions called cations. These ions
attract each other.
• How do you calculate the net charge of ions?
11 protons, 11 electrons
- +1 charge 11 protons 10 electrons, vice versa
• How many electrons does each energy level in an atom hold?
- Level 1: 2
- Level 2: 8
- Level 3: 18
- Level 4: 32
What is a valence shell
, - the outermost shell of an atom containing the valence electrons.
• What are valence electrons?
- negatively charged particle, located in the outermost shell of an atom, that can be transferred to or
shared with another atom.
Water Molecules
• What type of bonds are found within the H2O molecule?
- Polar Covalent bonds result in hydrogen bonding
• How does the electronegativity of oxygen compare to hydrogen?
- oxygen region has a partial negative charge stronger electronegativity, and the hydrogen
atom regions have partial positive charges
• How are water molecules attracted to one another?
Hydrogen bonds, Cohesion: like substance attract
pH, Acidity, Basicity
• What is the difference between an acid and a base?
- An acid is any hydrogen-containing substance that is capable of donating a proton (hydrogen ion)
to another substance. A base is a molecule or ion able to accept a hydrogen ion from an acid.
• How does H+ ion concentration relate to pH measurement?
- The overall concentration of hydrogen ions is inversely related to its pH and can be measured on
the pH scale (Figure 1). Therefore, the more hydrogen ions present, the lower the pH; conversely,
the fewer hydrogen ions, the higher the pH.
• Does a high H+ concentration result in an acidic or basic solution?
- Acids increase the concentration of H+ ions in a solution
• What is the range on the pH scale for an acid or a base?
- Below 7=acidic
- Above 7=basic
Functional groups
• Be able to recognize functional groups in a structure
Methyl groups: nonreactive but they serve as a biological tag on molecules (CH3)
Hydroxyl group (-OH)- hydrophilic
- Hydrogen atom that forms a polar covalent bond
- Improved solubility
- Organic compounds with hydroxyl groups are alcohols and their names typically end in –ol
Atomic number: is the number of protons in its nucleus (number at the top)
Mass number: is the sum of protons PLUS neutrons in the nucleus
- number of protons = atomic number.
- number of electrons = atomic number.
- number of neutrons = mass number - atomic number.
Isotopes
• How do isotopes of the same element differ from each other?
An isotope is one of two or more forms of the same chemical element. Different isotopes of an element
have the same number of protons in the nucleus, giving them the same atomic number, but a different
number of neutrons giving each elemental isotope a different atomic weight.
Electronegativity
• What is the most electronegative atom on the periodic table?
Fluorine
• How does electronegativity affect electrons in a covalent bond?
The more strongly an atom attracts the electrons in its bonds, the larger its electronegativity. Electrons in
a polar covalent bond are shifted toward the more electronegative atom; thus, the more electronegative
atom is the one with the partial negative charge.
Ionic Bonds
• What is an ionic bond? How is it formed?
electrovalent bond, type of linkage formed from the electrostatic attraction between oppositely
charged ions in a chemical compound
- form between two or more atoms by the transfer of one or more electrons between atoms.
Electron transfer produces negative ions called anions and positive ions called cations. These ions
attract each other.
• How do you calculate the net charge of ions?
11 protons, 11 electrons
- +1 charge 11 protons 10 electrons, vice versa
• How many electrons does each energy level in an atom hold?
- Level 1: 2
- Level 2: 8
- Level 3: 18
- Level 4: 32
What is a valence shell
, - the outermost shell of an atom containing the valence electrons.
• What are valence electrons?
- negatively charged particle, located in the outermost shell of an atom, that can be transferred to or
shared with another atom.
Water Molecules
• What type of bonds are found within the H2O molecule?
- Polar Covalent bonds result in hydrogen bonding
• How does the electronegativity of oxygen compare to hydrogen?
- oxygen region has a partial negative charge stronger electronegativity, and the hydrogen
atom regions have partial positive charges
• How are water molecules attracted to one another?
Hydrogen bonds, Cohesion: like substance attract
pH, Acidity, Basicity
• What is the difference between an acid and a base?
- An acid is any hydrogen-containing substance that is capable of donating a proton (hydrogen ion)
to another substance. A base is a molecule or ion able to accept a hydrogen ion from an acid.
• How does H+ ion concentration relate to pH measurement?
- The overall concentration of hydrogen ions is inversely related to its pH and can be measured on
the pH scale (Figure 1). Therefore, the more hydrogen ions present, the lower the pH; conversely,
the fewer hydrogen ions, the higher the pH.
• Does a high H+ concentration result in an acidic or basic solution?
- Acids increase the concentration of H+ ions in a solution
• What is the range on the pH scale for an acid or a base?
- Below 7=acidic
- Above 7=basic
Functional groups
• Be able to recognize functional groups in a structure
Methyl groups: nonreactive but they serve as a biological tag on molecules (CH3)
Hydroxyl group (-OH)- hydrophilic
- Hydrogen atom that forms a polar covalent bond
- Improved solubility
- Organic compounds with hydroxyl groups are alcohols and their names typically end in –ol
