What is the relationship between atomic mass and mass number?
A. They are the same.
B. Atomic mass is always greater than mass number.
C. Atomic mass and mass number are not related.
D. Atomic mass is very close to mass number but with some deviation in the decimal places.
Atomic mass is very close to mass number but with some deviation in the decimal places.
Atomic mass is also known as atomic weight and is the weighted average mass of an atom of an element based on the relative natural abundance of that element’s isotopes.
 |
The mass number, on the other hand, is a count of the total number of protons and neutrons in an atom’s nucleus.
Choice A is incorrect because atomic mass and mass number do not mean the same thing.
Choice B is incorrect because atomic mass is not always greater than mass number.
Choice C is incorrect because atomic mass and mass number are related.
Therefore, the Correct Answer is D.
More Questions on TEAS 7 Science
-
Q #1: Which of the following statements about bacteria and archaea is true?
A. A. Bacteria have a true nucleus while archaea do not
B. B. Archaea reproduce by spores while some bacteria reproduce by fission.
C. C. Bacteria can perform photosynthesis while archaea cannot.
D. D. Archaeal and bacterial flagella are constructed similarly.
Answer Explanation
Bacteria can perform photosynthesis while archaea cannot. Many types of bacteria can generate oxygen from sunlight through photosynthesis, while archaea cannot perform this process.
Choice A is incorrect because neither bacteria nor archaea have a true nucleus. Both are prokaryotic organisms. Choice B is incorrect because archaea reproduce by fission, fragmentation, or budding, while bacteria can produce spores and divide sexually or asexually. Choice D is incorrect because archaeal and bacterial flagella are constructed differently.
-
Q #2: Which type of lymphocyte is capable of killing tumor cells and infected cells without prior sensitization?.
A. Helper T cells.
B. B cells.
C. Natural killer cells.
D. Cytotoxic T cells .
Answer Explanation
Natural killer cells.
Natural killer (NK) cells are large granular lymphocytes that are capable of destroying cells infected by viruses or bacteria and susceptible tumor cells without prior sensitization and restriction by MHC antigens.
Helper T cells (choice A) are a type of white blood cell that helps other immune cells respond to infections but do not directly kill infected or tumor cells.
B cells (choice B) are a type of white blood cell that produces antibodies to fight infections but do not directly kill infected or tumor cells.
Cytotoxic T cells (choice D) are a type of white blood cell that can kill infected or tumor cells but require prior sensitization to do so.
-
Q #3: How do neurons communicate with each other?
A. Through electrical signals only
B. Through chemical signals only
C. Through electrical and chemical signals
D. Through mechanical signals only.
Answer Explanation
Neurons communicate with each other through both electrical and chemical signals.
The electrical signal, or action potential, runs from the cell body area to the axon terminals, through a thin fiber called axon.
Neurons also communicate with one another at junctions called synapses.
At a synapse, one neuron sends a message to a target neuron—another cell.
Most synapses are chemical; these synapses communicate using chemical messengers.
Choice A is incorrect because neurons communicate not only through electrical signals but also through chemical signals.
Choice B is incorrect because neurons communicate not only through chemical signals but also through electrical signals.
Choice D is incorrect because neurons do not communicate through mechanical signals.
