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4 years ago

What did Democritus think that matter was made of?

Chemistry

1 answer:

soldi70 [24.7K]4 years ago

5 0

Democritus believed matter was made up of small particles. He introduced the idea of the atom

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Explain how the law of conservation of mass necessitates our balancing all chemical equations.

denis23 [38]

The law of conservation of mass states that energy can neither be created, nor destroyed. It applies to all the chemical equations because everything is about matter. Changing one chemical to another, changing forms, shapes, colors, types to other ones. But in each and every single process of this universe, nothing is created or destroyed. It's just the simplest to the most complex transfers of energy throughout the universe.
I hope this helped.

5 0

3 years ago

The rate of diffusion of gas A is double the rate of gas B. The ratio of their molecular weight is

Dafna1 [17]

Answer:

Ratio is 4:1

Explanation:

from graham's law of gaseous diffusion:

${ \bf{ \frac{R _{A} }{R_{B} } = \sqrt{ \frac{M_{A} }{M_{B}} } }}$

but Ra = 2Rb:

${ \sf{ (\frac{2}{1} ) {}^{2} = \frac{M _{A}}{M _{B} } }} \\ \\ { \sf{\frac{M _{A}}{M _{B} } = \frac{4}{1} }} \\ \\ {M _{A}} : {M _{B} } = 4 :1$

4 0

3 years ago

What is the temperature of 0.5 moles of water vapor that occupies 120 dm3 and applies a pressure of 15,000 Pa to its container?

MArishka [77]

Use the ideal gas law:

PV = nRT

so, T = PV / nR

n=0.5
V= 120 dm^3 = 120 L (1 dm^3 = 1 L)
R = 1/12
P = 15,000 Pa = 0.147 atm (1 pa = 9.86 10^{-6} )

Put the values:

T = PV / nR
T = (0.147) (120) / (0.5) (1/12)
T= 426 K

6 0

3 years ago

What is the name of the industry that produces solvents, lubricants, polymers and detergents?

fredd [130]

Answer:

the petrochemical industry

Explanation:

"Petrochemicals are the chemical products obtained from petroleum by refining. Some chemical compounds made from petroleum are also obtained from other fossil fuels, such as coal or natural gas, or renewable sources such as maize, palm fruit or sugar cane." - Textbook excerpt

4 0

3 years ago

Rank the ions in each set in order of increasing size, and explain your ranking:

Paha777 [63]

Explanation:

Lithium, sodium and potassium are all group 1A elements and when we move down a group then there occurs an increase in atomic size of the elements. As lithium is the smallest and potassium being the largest so, when each of them will lose an electron and obtain a positive charge then size of lithium will further decrease.

Therefore, ions are ranked according to their increase in size as follows.

$Li^{+} < Na^{+} < K^{+}$

When an atom tends to gain electrons then it acquires a negative charge. This means that size of the atom increases.

So, more is the negative charge present on an atom more will be its atomic size. Therefore, correct order of increasing size for $Se^{2-}, Rb^{+}, Br$ is as follows.

$Br < Rb^{+} < Se^{2-}$

Similarly, order of increasing size of $O^{2-}, F^{-}, N^{3-}$ is as follows.

$F^{-} < O^{2-} < N^{3-}$

5 0

3 years ago