What is evidence of a physical change. A.ice melts B.silver tarnishes C.biycicle rusts

Select all that apply to organic compounds,

ki77a [65]

Answer:

Organic compounds can be synthesized in a laboratory setting

Organic compounds contain carbon

There are hundreds of thousands of organic compounds,

Explanation:

Organic compounds are compounds that are found in life i.e plants and animals. The bulk of compounds that makes up living organisms are called organic compounds.

The idea that organic compounds can only be found in living organisms has been proven wrong by the synthesis of urea in the laboratory.

Organic chemistry studies compounds of carbons with the exception of oxides, carbides and carbonates.

All these other compounds of carbon apart from the above listed ones are called organic compounds.

3 0

3 years ago

Each year, due to growing population and energy demands, the United States faces increasing dependency on conventional fossil fu

laiz [17]

Answer:

A) (i) 4*10^12 Ibs , (ii) 600 * 10^9 Ibs

(iii)

Wind energy is a clean energy : this is because there is no consumption of fossil fuels when using wind energy to generate electricity
Wind energy is a renewable energy : wind is reusable and it is always available for use

B) The use of bricks or stone that can absorb the solar heat easily when the sun rays heat them up and this solar heat absorbed . is a typical example of a passive solar heating system.

C) Advantage : It is mostly cost free

disadvantage : there is no storage mechanism

Explanation:

A) Given that U.S uses roughly 4 million Gigawatt-hours per year in electricity and 50% of the electricity comes from coal

i) Determine how much carbon dioxide is released from burning coal each year

since 50% of electricity comes from coal

The Total energy produced by coal =2*10^12 Kw-h. also

1.0 kilowatt-hour of coal burned releases 2 lbs.

hence the Total amount of Carbon dioxide released from burning coal each year = 2 * 2 * 10^12 = 4 * 10^12 Ibs

ii) Determine the reduction of carbon dioxide entering the atmosphere each year if coal usage could be reduced by 15% by utilizing solar energy

= 15% 0f 4*10^12

reduction of coal usage by 15% = 600 * 10^9 Ibs hence the amount of coal entering the atmosphere is reduced by 600 * 10^9 Ibs

iii) Advantages of using wind energy to generate electricity

Wind energy is a clean energy : this is because there is no consumption of fossil fuels when using wind energy to generate electricity
Wind energy is a renewable energy : wind is reusable and it is always available for use

B) Passive solar heating system

The use of bricks or stone that can absorb the solar heat easily when the sun rays heat them up and this solar heat absorbed . is a typical example of a passive solar heating system.

C) advantage and disadvantage of solar heating system

Advantage : It is mostly cost free

disadvantage : there is no storage mechanism

5 0

3 years ago

Arrange the following measurements, in seconds, from the greatest bias to the least bias. 6.63 ± 0.01 s, 6.6 ± 0.1 s, 6.52 ± 0.0

lord [1]

I understand here "bias" to be the uncertainty of measurements. So the order will be the following:

6.4 ± 0.5 s
6.6 ± 0.1 s,
6.63 ± 0.01 s,
6.52 ± 0.05 s,

(notice how the second number, the one behind the symbol ± gets smaller, as the bias gets smaller).

6 0

4 years ago

What is the best definition of low electromagnetic energy?

inysia [295]

The best definition of low electromagnetic energy would be A. Low electromagnetic energy has long wavelengths and low frequency.

6 0

3 years ago

Need help with this

Lunna [17]

Answer:

C option is the correct answer

3 0

3 years ago