Question | Answer |
atoms consist of 3 subatomic particles: | protons
neutrons
electrons |
what is ground level? | if all electrons in an atom are in it's lowest energy level |
what is excited state? | when an atom absorbs energy, its electrons move to a higher energy level |
what is an isotope? | atoms of one element that vary only in the number of neutrons in the nucleus |
what is half-life? | half life enables us to measure the age of fossils or to estimate the age of the earth |
what are radioisotopes? | A version of a chemical element that has an unstable nucleus and emits radiation during its decay to a stable form |
what is tracer? | A radioactive molecule that can be sent through the body's circulatory or urinary system, with its progress followed by a radiation-sensitive machine. |
bonds form when: | two atomic nuclei attract the same electrons |
two main types of bonds: | ionic
covalent |
ionic bonds result from: | the transfer of elecrtons |
what is an anion | a negative ion |
an atom that gains electrons become: | an anion |
what is a cation? | a positive ion |
an atom that looses electrons become: | a cation |
covalent bonds form when atoms: | share electrons |
covalent bonds form when atoms share electrons. what structure results from this? | a molecule |
when electrons are shared equally between two identical atoms the bond is: | nonpolar |
when electrons are shared unequally the bond is referred to as: | polar |
hydrophilic means: | water loving |
hydrophobic means: | water hating |
since so many substances dissolve in water, water is known as the: | universal solvent |
hydrophobic applies to non polar substances, which are: | miscible with or will dissolve with lipids |
Water is a very (blank) molecule | polar |
two molecules are held together by | hydrogen bonding |
water has 4 important things | high specific heat, high heat of vaporization, is the universal solvent, exhibits strong cohesion tension |
ice floats because it's (blank) dense than water | less |
what is pH | a measure of the acidity and the alkalinity of a solution |