biology 1150 test two ( basic chemistry and water ) Flashcards
which of the following has the smallest size
a. neuron
b. molecule of glucose
c. atom of oxygen
d. cell
a. neuron
the number of electrons always equals
a. number of neutrons
b. number of protons and neutrons
c. number of protons
d. none of the above
c. number of protons
isotopes differ in number of electrons
a. true
b. false
b. false
atomic theory says
all living and non living things are made up of atoms
atoms are made of
sub atomic particles (protons, neutrons, & electrons)
what does the atomic number tell us
number of protons
common elements found in organisms are (6)
carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur
the shell closest to the nucleus can hold ___ electrons
2
what does the atomic mass tell us
number of protons plus neutrons
what are covalent bonds
when atoms share electrons
stable atom means
outmost shell is full
what are ionic bonds
when atoms transfer electrons
what is a non-polar covalent bond in hydrogen molecule
electrons are superimposed on the bond to indicate that they are halfway between the two atoms, shared equally
what is a polar covalent bond in water molecules
electrons are not shared equally so partial charges exist on the O and H atoms
which is more electronegative
a. oxygen
b. hydrogen
a. oxygen
protons have a ____ charge
positive
electrons have a ____ charge
negative
neutrons have ____ charge
no
neutral atom has
same number of electrons and protons
atoms form bonds with other atoms to ____
become stable
the ____ of water makes it a great solvent
polarity
how does a water molecule form
oxygen atom covalently bonds with two hydrogen atoms
hydrogen bonds form because
hydrogen atoms from one water molecule are attracted to the oxygen atoms of other water molecules
hydrogen bonds are _____ than covalent bonds
weaker
human body is made up of ___% water
67
water serves as the _____ to chemical reactions to occur
media
water is polar and electrons are _____ ______ oxygen
pulled toward
hydrogen bonds form between _____ molecules
water
define cohesion binding
binding between like molecules (water to water)
define adhesion binding
binding between unlike molecules (water with glass)
transportation of materials in the blood occurs due to
cohesion and adhesion binding properties
water has _____ capacity for _______ energy
high / absorbing
solid water is _____ dense than liquid water
less
molecules are ________ __________ in ice
evenly spaced
molecules are ________ _______ in liquid form water
closer together
when placed in water, acids release _______ ions
hydrogen
when placed in water, bases release ________ ions
hydroxide
the lower the ph the ______ the acidity
higher
the higher the ph, the ______ _______ the solution
more basic
water can act as both an acid and a base
a. true
b. false
a. true
pure water pH is
7
pH > 7
base / alkaline
pH < 7
acidic
weak bonds formed between water molecules are ______ bonds
a. covalent
b. compound
c. hydrogen
d. ionic
c. hydrogen
what property of water provides the cooling effect of sweating
a. cohesiveness
b. high heat capacity
c. high heat of vaporization
d. surface tension
c. high heat of vaporization
most body fluids are found in which range of the pH scale
a. 1-5
b. 6-8
c. 9-14
d. all body fluids are 7
b. 6-8
solution a has a pH of 6. solution b has a pH of 9. which is false
a. solution a have more H+ than solution b
b. solution b is basic and solution a is acid
c. both solutions a and b are acids
d. solution b has more OH- than H+ ions
c. both solutions a and b are acids
