chemistry of life Flashcards
(39 cards)
what are the six main elements in bio?
carbon, hydrogen, nitrogen, oxygen, phosphate, and sulfur
what is an atom?
smallest unit of matter that has properties of an element
what are the three subatomic particles?
protons, neutrons, and electrons
where are protons located?
nucleus of atom
where are neutrons located?
the nucleus of the atom
where are electrons located
energy levels/valence shells
what charge does a proton have, and what does it determine?
positive charge, determine element
what charge do neutrons have, and what do different numbers of neutrons mean?
no electrical charge, different number of neutrons = isotopes
what charge do electrons have, and what do they determine?
negative, determine chemical bonding abilities
what are isotopes?
atoms in an element that differ in number of neutrons
how do you differentiate radioactive isotopes from normal atoms?
they give off detectable energy
what do radioactive isotopes allow to happen?
trace atoms through metabolic process, label and identify molecules, diagnosing medical disorders, dating fossils
why do isotopes have the same chemical properties as regular atoms of the element?
same number of electrons
in what cases do atoms share or transfer electrons?
when they have incomplete valence shells
what are chemical bonds?
atoms staying close together
what types of chemical bonds are strong?
covalent and dry ionic
what types of chemical bonds are weak?
aqueous ionic and hydrogen bonds
what are covalent bonds?
sharing of a pair of valence electrons by two atoms
what is a molecule?
two or more atoms held together by covalent bonds
what do covalent bonds form?
a cell’s molecules
when you form a covalent bond…
chemical energy is stored
when you break a covalent bond…
chemical energy is released
what is electronegativity?
an atom’s attraction for the electrons in a covalent bond
the more electronegative an atom…
the more strongly it pulls shared electrons toward itself
