Answer:
The convection process plays an important role in the liquid. Due to the increasing heat supply or high amount of temperature, the fluid gets heated up, as a result of which it becomes warm, less dense and eventually rises up forming convection cells.
In the interior of the earth, the hot molten rocks get heated up due to the heat supplied by the core of the earth. This makes the magma warm and less dense and rises upward forming convection currents in the mantle.
This convection process is similar to the convection cells that form in the atmosphere, where the hot, less dense air rises up in the atmosphere forming a low-pressure zone. This uprising air forms convection cells, in which the warm air rises and as it rises high in the atmosphere, the temperature becomes low, making the air cold and it eventually sinks.
2. A dilute solution means that the amount of solvent (water, for this particular case) is significantly larger than the solute (salt). Thus, the answer is D.
6. John Dalton's atomic theory states that matter is made up of tiny indestructible objects called matter. The theory also indicates that although same elements have the same atoms, each element have unique set atoms that deinfe them. From this, we can conclude that the wrong assumption is C.
9. Atoms, by default, are electrically neutral. When an atom loses or gains electron/s, then they become ionized atoms or commonly called as ions. Thus, ionized atoms imply unequal number of protons and electrons. This means the answer must be A.
11. Analgesics are commonly used to relieve pain. Thus, the answer is C.
14. Adding up the atomic mass of the individual atoms will give you the molar mass of a compound. Therefore, the answer is B.:
15. The pH scale provides us the alkalinity or acidity of a solution based on the value. A value between 0 to 6 indicates that the solution is acidic. 7 is considered neutral and a value between 7 and 14 indicates that the solution is basic. Thus, the answer is D.
19. An element has consistent properties and can no longer be further identified into having individual properties. Thus, the answer is A.
20. The valence of an element dependeds on the number of electrons on the outermost shell. Thus, it is equal to the number of charge negative or positive charges on the ion. Hence, we have A<span>.
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The size of the force varies inversely as the square of the distance between the two charges. Therefore, if the distance between the two charges is doubled, the attraction or repulsion becomes weaker, decreasing to one-fourth of the original value.
That's false.
The definition of momentum is (mass) x (speed), so they must be multiplied.
"20,000 kg-m/s" has the correct units resulting from multiplication, but the number could only be the result of division.
Answer:
The kilogram (kg) is defined by taking the fixed numerical value of the Planck constant h to be 6.62607015 ×10−34 when expressed in the unit J s, which is equal to kg m2 s−1, where the meter and the second are defined in terms of c and ∆νCs.
