Answer please I need help

dem82 [27]

Answer:

D: Water is polar, so it can form attractions to and pull apart molecules of many types of substances.

Explanation:

Water is an excellent solvent simply because its polar water molecules usually form hydrogen bonds with ions and polar molecules, thereby allowing the ionic and polar covalent compounds to easily disperse easily in water.

Thus, the correct option is; D

7 0

3 years ago

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Why are astronauts weightless in the Space Station? You may find it helpful to watch the video "Newton's Laws of Motion." Why ar

Zolol [24]

Answer:

B) Because the Space Station is constantly in free-fall around the Earth.

Explanation:

Anything that is falling experiences an upward force on them. For example when a person is going down in a lift they will experience something that is pushing them upwards. This happens due to the fact that the total acceleration the body is feeling is less than the acceleration due to graviity.

The force on a body which is falling is

$F=m(g-a)$

Where,

m = Mass of object

g = acceleration due to gravity

a = acceleration the object is experiencing.

a = g. So, the force becomes zero and the object experiences weightlessness.

Hence, the astronauts in the space station experience weightlessness due to fact that the Space Station is constantly in free-fall around the Earth.

7 0

3 years ago

How is modeling useful in studying the structure of the atom?

Mandarinka [93]

Modelling the structure of the atom is important because modeling replaces the real system with something similar but easier to examine. Option B

<h3>What is modeling?</h3>

A model is a representation of reality. We know that a model could help us to recreate reality in a manner that we could be able to relate fully with it. A model could be used also a means of explanation.

The atomic models that we have usually help us to understand more abut the atom. Therefore, modelling the structure of the atom is important because modeling replaces the real system with something similar but easier to examine. Option B

Learn more about modelling the atom:brainly.com/question/1596638

#SPJ1

6 0

2 years ago

An extended period when temperatures are well below average is known as a/an

Alecsey [184]

It would be a cold wave.
Ice ages occur when the temperatures are extremely cold.(long-term)

3 0

3 years ago

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Solution A has a speciﬁc heat of 2.0 J/g◦C. Solution B has a speciﬁc heat of 3.8 J/g◦C. If equal masses of both solutions start

fgiga [73]

Answer: 2. Solution A attains a higher temperature.

Explanation: Specific heat simply means, that amount of heat which is when supplied to a unit mass of a substance will raise its temperature by 1°C.

In the given situation we have equal masses of two solutions A & B, out of which A has lower specific heat which means that a unit mass of solution A requires lesser energy to raise its temperature by 1°C than the solution B.

Since, the masses of both the solutions are same and equal heat is supplied to both, the proportional condition will follow.

<em>We have a formula for such condition,</em>

$Q=m.c.\Delta T$ .....................................(1)

where:

$\Delta T$ = temperature difference

Q= heat energy

m= mass of the body

c= specific heat of the body

<u>Proving mathematically:</u>

<em>According to the given conditions</em>

we have equal masses of two solutions A & B, i.e. $m_A=m_B$

equal heat is supplied to both the solutions, i.e. $Q_A=Q_B$

specific heat of solution A, $c_{A}=2.0 J.g^{-1} .\degree C^{-1}$

specific heat of solution B, $c_{B}=3.8 J.g^{-1} .\degree C^{-1}$

$\Delta T_A$ & $\Delta T_B$ are the change in temperatures of the respective solutions.

Now, putting the above values

$Q_A=Q_B$

$m_A.c_A. \Delta T_A=m_B.c_B . \Delta T_B\\\\2.0\times \Delta T_A=3.8 \times \Delta T_B\\\\ \Delta T_A=\frac{3.8}{2.0}\times \Delta T_B\\\\\\\frac{\Delta T_{A}}{\Delta T_{B}} = \frac{3.8}{2.0}>1$

Which proves that solution A attains a higher temperature than solution B.

7 0

3 years ago