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3 years ago

6

If China has a population of 1,355,935,022 people and an area of 3,705,405 mi2028-02-04-03-00_files/i0160000.jpg, what is the po

pulation density of China?

1 answer:

mote1985 [20]3 years ago

4 0

The correct answer is D.) 366 people/mi

You might be interested in

Describe the contributions made by Oparin, Haldane, Miller, and Urey toward understanding the origin of organic molecules.

balu736 [363]

Answer:

The theory of Oparin and Haldane was based on the fact that the primitive atmosphere was very different from the current atmosphere, since energy was abundant on the young planet. Both proposed that the appearance of life was preceded by a period they called "chemical evolution."

On the other hand, Miller Urey made an experiment where it was shown that some organic components were formed spontaneously if they were simulating the conditions of the Earth's early atmosphere.

Explanation:

The first hypotheses about the origin of life on Earth were suggested by Oparin and Haldane, who worked independently. Oparin presented his ideas on the origin of life in the year of 1922 by publishing them in the year of 1924. For his part, Haldane published similar ideas in 1929, however, Haldane gave priority to Oparin in the formulation of the theory.

Oparin based his hypotheses using a model he called "coacervates", which are colloidal systems formed by macromolecules that formed in aqueous media and would have evolved to form cells with membranes. According to Oparin, living beings modified the primitive atmosphere and this would have prevented, the formation of life from inorganic substances.

The Miller and Urey experiments helped reinforce the theory that the first way of life was created spontaneously through chemical reactions. However, there are still many scientists who are not convinced.

8 0

3 years ago

One solution contains 14.9 g KCl in exactly 10 mL of solution. What is the molarity of the solution? molar mass KCI = 74.5 g/mol

Lorico [155]

Answer:

20

Explanation:

6 0

3 years ago

I need to check some chemistry questions. Help with any question is appreciated! :) Please include an explanation with your conc

finlep [7]

1. 4.67 kg; 2. 4.8 ×10^5 kg; 3. 0.106 cm^3; 4. 1.7 g/cm^3

<em>Q1. Mass of Hg </em>

Mass = 345 mL × (13.53 g/1 mL) = 4670 g = 4.67 kg

<em>Q2. Mass of Pb </em>

<em>Step 1</em>. Calculate the <em>volume of the Pb</em>.

<em>V = lwh</em> = 6.0 m × 3.5 m × 2.0 m = 42.0 m^3

<em>Step 2</em>. Calculate the <em>mass of the Pb</em>.

Mass = 42.0 m^3 × (11 340 kg/1 m^3) = 4.8 × 10^5 kg

<em>Q3. Volume of displaced water </em>

Volume of Ag = 0.987 g × (1 cm^3/9.320 g) = 0.106 cm^3

<em>Archimedes</em>: volume of displaced water = volume of Ag = <em>0.106 cm^3</em>

<em>4. Density of metal </em>

<em>Step 1</em>. Convert <em>ounces to grams </em>

Mass = 3.35 oz × (28.35 g/1 oz) = 94.97 g

<em>Step 2</em>. Calculate the <em>volume in cubic inches </em>

<em>V = lwh</em> = 3.0 in × 2.5 in × 0.45 in = 3.38 in^3

<em>Step 3</em>. Convert <em>cubic inches to cubic centimetres</em><em> </em>

<em>V</em> = 3.38 in^3 × (2.54 cm/1 in)^3 = 55.3 cm^3

<em>Step 4</em>. Calculate the <em>density</em>

ρ = <em>m</em>/<em>V</em> = (94.97 g/55.3 cm^3) = 1.7 g/cm^3 (magnesium?)

4 0

3 years ago

I really need the answers please!

krek1111 [17]

1) D = 13.6 g / mL

2)ethyl alcohol weighs 158g

3)ρ _copper = 8.9 g $cm^{3}$

Explanation:

1)

D = m / V

=306.0 g / 22.5 mL

D= 13.6 g / mL

2)

density = mass / volume

mass = density × volume

=0.789g /ml × 200.0 ml

M=158g

Ethyl alcohol weighs 158g

3)

ρ (density) = Mass / Volume

ρ _copper = 1896 g / 8.4cm × 5.5cm × 4.6cm

= 1896g / 212.5 $cm^{3}$

ρ _copper=8.9 g $cm^{3}$

4 0

3 years ago

During chemical reactions the bonds between atoms break and new bonds form. Energy must be absorbed to break a bond, so breaking

ss7ja [257]

Answer:

The equation is: CuCO3(s) → CuO(s) + CO2(g)

Explanation:

Copper carbonate decomposes at high temperatures, generating the products carbon dioxide (CO2) and copper oxide (II) CuO. In this type of decomposition reaction, a substance is broken generating two different compounds.

7 0

3 years ago