Bio Unit 2 Flashcards
Learn the Nature and Properties of Matter (48 cards)
What is an atom?
the basic unit of chemical elements made up of subatomic particles
What are the subatomic particles?
protons, neutrons, electrons
What is the charge of a proton? Were is it located in the atom?
positive
in the nucleus
What is the charge of a neutron? Were is it located in the atom?
neutral
in the nucleus
What is the charge of a electron? Were is it located in the atom?
negative
in shells around the nucleus
What is an element?
a pure substance consisting of only one type of atom
How can you identify the atomic mass of an element?
last number on the block of an element
number of protons + number of neutrons
How can you identify the number of neutrons in an element?
atomic mass - atomic number
How can you identify the number of protons in an element?
atomic number
How can you identify the atomic number of an element?
first number on the block of an element
number of protons
How can you identify the number of electrons in an element?
atomic number (assuming the element is neutral)
How can you tell if an element is an ion (based on the element card)? How can you identify the number of electrons in an ion?
If the element has a (+) or (-) or a number and a (+) or (-) listed after the element symbol, that means that the element is charged.
(+) means that the element is positively charged and has lost the same number of electrons as the number before the plus sign (no number = 1 electron lost)
(-) means that the element is negatively charged and has gained the same number of electrons as the number before the plus sign (no number = 1 electron gained)
What are isotopes?
versions of an element with different numbers of neutrons but the same chemical properties
What is a radioactive isotope? What do they allow for?
when the nuclei in an elements are unstable and break down at a constant rate over time
carbon dating, detecting cancer, and killing bacteria
What are chemical compounds? How are they different from pure elements?
a substance formed by the chemical combination of two or more elements in definite proportions (e.g. H2O = 1 oxygen atom, 2 hydrogen atoms)
their physical and chemical properties are different
What are hydrogen bonds?
a weak bond between two molecules formed when the partial negativity of the oxygen in one molecule attracts to the partial positivity of hydrogen in another
What are covalent bonds?
a bond formed when two atoms’ shells overlap, and electrons can freely flow between the two
What is electronegativity?
the tendency of an atom to attract more electrons in a covalent bond, making that atom partially negative
What is an ion?
An atom with a positive or negative electrical charge
What are ionic bonds? What do they cause?
a bond formed when one or more electrons are transferred from one atom to another
atoms becoming charged
What is a cation? What made it a cation?
a positively charged ion
lost electrons to another atom
What is an anion? What made it an anion?
a negatively charged ion
gained electrons from another atom
What are the properties of water?
polarity, cohesion, adhesion, high specific heat, less dense as a solid
What is polarity? How does it affect bonds?
the uneven distribution of charges among atoms connected by a chemical bond
when charges are uneven, the negative parts attract the positive parts of other atoms (and vice versa), forming hydrogen bonds