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3 years ago

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Which statement correctly describes a scientific theory? A. It is accepted as true indefinitely. B. It is based on repeated inve

stigations. C. It is equivalent to a scientific law. D. It is accepted as false.

1 answer:

Gwar [14]3 years ago

4 0

The correct answer is B

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Decide which element probably has a boiling point most and least similar to the boiling point of cesium.

natka813 [3]

Answer:

Take a look at the attachment below

Explanation:

Take a look at the periodic table. As you can see, Rubidium is the closest element to Cesium, and happens to have the closest boiling point to Cesium, with only a difference of about 30 degrees.

Respectively, you would think that fluorine should have the least similarity to Cesium with respect to it's boiling point, considering it is the farthest away from the element out of the 4 given. This is not an actual rule, there are no fixed trends of boiling points in the periodic table, there are some but overall the trends vary. However in this case fluorine does have the least similarity to Cesium with respect to it's boiling point, a difference of about 1,546.6 degrees.

<em>Hope that helps!</em>

5 0

3 years ago

You’ve been waiting for the bus and your hands become cold. When you get onto the bus and sit down, you put your hands under you

snow_tiger [21]

Explanation:

The <u>First Law of Thermodynamics</u> states that energy cannot be created or destroyed in an isolated system. In other words, energy can be converted from one form into another, but it cannot be created nor destroyed.

<u>Conduction</u> is the transfer of energy from one molecule to another by direct contact. This transfer occurs when molecules hit against each other, which can take place in solids, liquids, and gases.

When you put your cold hands under your legs to warm your hands up, the heat energy from your legs is being transferred to your hands through conduction. However, since energy cannot be created, there is no extra heat energy that can instantaneously replace the heat created by your legs.

3 0

3 years ago

Read 2 more answers

What order must the earth, the sun, and the moon be in to be a lunar eclipse?

zhannawk [14.2K]

A total lunar eclipse takes place when the Earth comes between the Sun and the Moon and covers the Moon with its shadow. When this happens, the Moon can turn red, earning it the nickname of Blood Moon.

3 0

3 years ago

Water containing large amounts of Mg2+and Ca2+ions is said to be hard because it is hard to make soap lather in the water. True

mafiozo [28]

Answer:True

Explanation:

Water is said to be hard when it contains calcium ions or magnesium ions dissolved in it. These ions are able to react with soap in such a way that the soap is prevented from forming lather with the water. Hard water occurs when water passes over calcium or magnesium bearing minerals and dissolves some of it. Hardness due to the presence of calcium ions can easily be removed by boiling the water.

8 0

3 years ago

Anybody good at chemistry?

Luba_88 [7]

Answer:

Explanation:

1)

Given data:

Mass of lead = 25 g

Initial temperature = 40°C

Final temperature = 95°C

Cp = 0.0308 j/g.°C

Heat required = ?

Solution:

Specific heat capacity: Cp

It is the amount of heat required to raise the temperature of one gram of substance by one degree.

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT = Final temperature = initial temperature

ΔT = 95°C - 40°C

ΔT = 55°C

Q = 25 g × 0.0308 j/g.°C × 55°C

Q = 42.35 j

2)

Given data:

Mass = 3.1 g

Initial temperature = 20°C

Final temperature = 100°C

Cp = 0.385 j/g.°C

Heat required = ?

Solution:

Specific heat capacity: Cp

It is the amount of heat required to raise the temperature of one gram of substance by one degree.

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT = Final temperature = initial temperature

ΔT = 100°C - 20°C

ΔT = 80°C

Q = 3.1 g × 0.385 j/g.°C × 80°C

Q = 95.48 j

3)

Given data:

Mass of Al = ?

Initial temperature = 60°C

Final temperature = 30°C

Cp = 0.897 j/g.°C

Heat released = 120 j

Solution:

Specific heat capacity: Cp

It is the amount of heat required to raise the temperature of one gram of substance by one degree.

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT = Final temperature = initial temperature

ΔT = 30°C - 60°C

ΔT = -30°C

120 j = m × 0.897 j/g.°C × -30°C

120 j = m × -26.91 j/g

m = 120 j / -26.91 j/g

m = 4.46 g

negative sign show heat is released.

4)

Given data:

Mass of ice = 1.5 g

Change in temperature = ?

Cp = 0.502 j/g.°C

Heat added= 30.0 j

Solution:

Specific heat capacity: Cp

It is the amount of heat required to raise the temperature of one gram of substance by one degree.

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT = Final temperature = initial temperature

30.0 j = 1.5 g × 0.502 j/g.°C × ΔT

30.0 j = 0.753 j/°C × ΔT

30.0 j /0.753 j/°C = ΔT

39.84 °C = ΔT

3 0

3 years ago