Answer:
B. Gravity held the pieces of forming planets together.
c. Gravity pulled most of the matter into the center of the solar system
D. Gravity caused the planets and Sun to have spherical shapes.
Explanation:
When a collection of grains pulled together by their gravitational forces would keep in by the gravity of a star, it would eventually became bigger to the point a planet was formed.
The sun's strong gravitational force pulled most of the matter around it to the center of the solar system.
The spherical shape of planets is a result of their gravity pulling equally from all sides, shaping it into a sphere.
Answer:
0.21 M. (2 sig. fig.)
Explanation:
The molarity of a solution is the number of moles of the solute in each liter of the solution. The unit for molarity is M. One M equals to one mole per liter.
How many moles of NaOH in the original solution?
,
where
is the number of moles of the solute in the solution.
is the concentration of the solution. 
for the initial solution.
is the volume of the solution. For the initial solution, 
for the initial solution.
.
What's the concentration of the diluted solution?
.
- is the number of solute in the solution. Diluting the solution does not influence the value of .
for the diluted solution. - Volume of the diluted solution:
.
Concentration of the diluted solution:
.
The least significant number in the question comes with 2 sig. fig. Keep more sig. fig. than that in calculations but round the final result to 2 sig. fig. Hence the result: 0.021 M.
Answer: the correct option is that batteries (do NOT require a continuous source of fuel).
Explanation:
A battery can be classified as an electrochemical cell that has the ability to produce electric current. They do NOT require a continuous supply of fuel because it contains all the reactants needed to produce electricity. Below are some examples of batteries that are commonly used:
--> Primary battery: This is a single use battery because it can't be recharged. A typical example is the dry cell.
--> Secondary battery: This type of battery can be recharged. They are used as a power source for smartphones, electronic tablets, and automobiles.
A FUEL CELL is known as a device that converts chemical energy into electrical energy. Fuel cells are similar to batteries but require a continuous source of fuel, often hydrogen. They will continue to produce electricity as long as they are constantly resupplied with reactants. Hydrogen fuel cells have been used to supply power for satellites, space capsules, automobiles, boats, and submarines.
Explanation:
From your information above, assume 1 month is 28 days
1 days=24hours ; 28 days=672 hours (just multiply 1 days with 28)
1 hour=60minutes ; 672 hours=40,320 minutes
.. 1 month=40,320 minutes
The correct answer is that chemical changes form new compounds. Chemical change is a change where the substance changes in identity or form new substances after undergoing a process. On the other hand, a physical change is a change in the properties of matter that does not change the identity of the substance.
