Answer:
D: to transport materials through the body.
Explanation:
A: to bring oxygen into the lung. is incorrect because it's respiratory system
B: to put carbon dioxide into all the blood vessels carbon dioxide is exhaled out of the body
C: to expel waste products from the body. is excretory system
Answer:
Certain things we think of as hard work, such as writing an exam or carrying a heavy load on level ground, are not work as defined by a scientist. The scientific definition of work reveals its relationship to energy—whenever work is done, energy is transferred.
For work, in the scientific sense, to be done, a force must be exerted and there must be motion or displacement in the direction of the force.
Note: Above question is incomplete: Complete question is read as
<span>According the the arrhenius theory, which species does an acid produce in an aqueous solution?
</span>A) hydrogen ions B) hydroxyl ions C) Sodium ions D) Chloride ion
.....................................................................................................................
Correct answer for above question is A) Hydrogen ions
Reason:
According the Arrhenius theory of acid and base, acid generates hydrogen ions in aqueous medium, while bases generates hydroxyl ions in aqueous medium.
Example of Acid:
HCl(aq) → H+(aq) + Cl-(aq)
Example of Base:
NaOH(aq) → Na+(aq) + OH-(aq)
A compound<span> is a </span>pure substance<span> composed of two or more different atoms chemically bonded to one another. A </span>compound<span> can be destroyed by chemical means. It might be broken down into simpler </span>compounds<span>, into its elements or a combination of the two.</span>
Answer:
Molecules move freely around since they don't have a definite shape. This is the reason water stays liquid and couldn't be gripped.
