Chapter 2 Flashcards
(29 cards)
How many chemical elements make up all living organisms?
25
What are the elements that make up ~96% of the human body?
O, C, N, H
Be able to recognize the elements that fall within the “remaining 4%” category.
includes elements like phosphorus, calcium, potassium, magnesium, sulfur, and micronutrients such as zinc, copper, and iron.
Be able to identify and recognize a trace element from the examples given.
iron, copper, zinc, iodine, and selenium.
Understand that atoms of elements combine to
form molecules.
Be able to recognize an example of a molecule.
combination of atoms
Understand the definition of an atom.
basic unit of a chemical element.
Understand the components of an atom
(proton, neutron and electron).
Know and understand the definition of atomic number.
number of protons in the nucleus of an atom.
Understand that the number of electrons in the outermost electron shell determines the
chemical properties of an element/atom.
Understand that the innermost electron shell contains
2 electrons, and the outermost can contain up to 8 electrons.
Be able to calculate the number of electrons in the outermost shell if given the atomic number.
Understand the consequences of having an incomplete outer electron shell.
An incomplete outer electron shell, also known as an incomplete valence shell, leads to an atom being unstable and highly reactive. Atoms with an incomplete outer shell tend to form chemical bonds with other atoms to achieve a stable, filled outer shell
Understand that when atoms gain or lose electrons,
they also gain or lose electrical charge; understand that a charged atom is an ion.
Understand that an ionic bond results from
the transfer of electrons and the resulting electrical charges between the two ions.
Understand that NaCl is an example of
a compound that is ionically bonded.
Understand that a covalent bond results from the
sharing of electrons between 2 atoms.
Be able to recognize that a molecule consists of
2 or more atoms covalently or ionically bonded together.
Know that ionic bonds are
strong, but covalent bonds are very strong.
Know that a molecule can consist of
2 or more different elements or 2 or more atoms of the same element.
Understand that polarity results from
the unequal sharing of electrons within a molecule.
Know that a polar molecule is
covalently bonded.
Know that water is an example of a
polar molecule (and the most important!).
Know that hydrogen bonds exist between
2 polar molecules, resulting from the attraction between (+) and (-) portions of molecules.
