Question 13 (mandatory) (3 points)
ions are atoms of the same element that have a different n...
Biology, 03.02.2020 13:57 jeremiahjohnsonclapg
Question 13 (mandatory) (3 points)
ions are atoms of the same element that have a different number of
question 13 options:
nuclei
electrons
neutrons
protons
nucleons
question 14 (mandatory) (3 points)
radium-226 is unstable. what is the process that allows the nucleus of radium-226 to become more stable?
question 14 options:
hydrogen bonding
radioactive decay
nuclear fusion
ionic bonding
covalent bonding
question 15 (mandatory) (3 points)
what parts of an atom can change during a nuclear reaction that cannot change during a chemical reaction?
question 15 options:
the number of electrons only
the number of protons and electrons
the number of neutrons and electrons
the number of protons and neutrons
question 16 (mandatory) (3 points)
traditional explosives use the energy released by chemical reactions. nuclear weapons use the energy released by nuclear reactions. why are nuclear weapons much more destructive than traditional explosives?
question 16 options:
chemical reactions always release more energy than they use
nuclear reactions can release much more energy than chemical reactions
chemical reactions always use more energy than they release
nuclear weapons always contain more chemicals than traditional explosive
chemical reactions can release much more energy than nuclear reactions
question 17 (mandatory) (3 points)
the nucleus of some isotopes will spontaneously undergo nuclear decay. these isotopes are said to be radioactive. what causes the nucleus of an isotope to be radioactive?
question 17 options:
exposure to toxic chemicals
the net charge of the atom
the attraction of protons to electrons
an unstable ratio of protons and neutrons
too many electrons in its orbitals
question 18 (mandatory) (3 points)
if a substance can be separated by physical means and it is not the same throughout, what is it?
question 18 options:
a pure substance
a compound
a heterogeneous mixture
an element
a homogeneous solution
question 19 (mandatory) (3 points)
if a substance cannot be separated by physical means or chemical means, it is
question 19 options:
a mixture
a solution
heterogeneous
a compound
an element
question 20 (mandatory) (3 points)
water vapor turning to frost is an example of .
question 20 options:
deposition
vaporization
sublimation
evaporation
freezing
question 21 (mandatory) (3 points)
what does the atomic number of an element represent?
question 21 options:
the mass of an atom
the number of protons in an atom
the number of neutrons in an atom
the total number of protons, neutrons, and electrons in an atom
the order in which the element was discovered
question 22 (mandatory) (3 points)
which of the following is a common property of noble gases?
question 22 options:
seeks to donate one to three electrons
have a full outer shell of electrons
are highly reactive
easily form chemical compounds
are good conductors of electricity
question 23 (mandatory) (3 points)
which type of element seeks to gain electrons?
question 23 options:
non-metals
noble gases
metals
isotopes
metalloids
question 24 (mandatory) (3 points)
if a material is ductile, it is most likely a .
question 24 options:
non-metal
noble gas
ion
metalloid
metal
question 25 (mandatory) (3 points)
what determines the properties of elements?
question 25 options:
the average atomic mass
the number of electron shells
the number of neutrons
the number of electrons that fill the outer shell
the total number of electrons
question 26 (mandatory) (3 points)
what is happening to the temperature of the substance before and after the phase changes?
question 26 options:
temperature increases before and after the phase changes.
temperature increases before the phase change and decreases after the phase change.
temperature stays the same before and after the phase changes.
temperature decreases before and after the phase changes.
temperature decreases before the phase change and increases after the phase change.
Answers: 2
Biology, 21.06.2019 19:50
After getting the slide and microscope ready, stella is eager to see the microscopic pond water specimen! she crouches around her microscope and aligns her eye with the microscope’s eyepiece. but she's only able to see a bright white light. at this point, no specimens or cells are visible on stella's pond water slide. after taking a moment to collect her thoughts, stella realizes she can't see any lifeforms because .
Answers: 3
Biology, 21.06.2019 22:00
Which of the following scenarios is an example of the bottleneck effect? answers a in south africa, much of the afrikaner population is descended from a small number of dutch colonists. in this population, this is an unusually high frequency of pseudoxanthoma elasticum (pxe), an elastic tissue disorder. b four white-tailed deer are introduced to a park in finland. thirty years after their introduction scientists compare the genes in the population and find that there is no variation. c during the industrial revolution, london's air became filled with soot. as a result, birds started eating more of the lighter moths because they were easier to spot than their darker counterparts. over time, the moth population changed so that there were more darker moths than lighter ones. d 10% of the population of american alligators in an area have the recessive trait albinism. a massive flood results in the death of 80% of the population. of the remaining population, 60% have the recessive trait of albinism.
Answers: 2
Biology, 22.06.2019 07:00
When proteins are being produced by a cell, scientist say that the genes are question 2 options: activated turned off replicated deactivated
Answers: 1
Biology, 22.06.2019 08:30
What do isotopes of uranium have the same number of? what do they have a different number of? a) same number of protons; different number of electrons b) same number of protons; different number of neutrons c) same number of electrons; different number of protons d) same number of neutrons; different number of protons
Answers: 1
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