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3 years ago

Which of these is a chemical change?

Physics

2 answers:

Radda [10]3 years ago

7 0

Anything that says burned is a chemical reaction or a chemical change. Here's a burning reaction.

C2H5OH + 302 ===> 2CO2 + 3H2O

This is the equation for burning alcohol (the kind you drink). When burned, the alcohol's reaction leaves a beautiful blue flame along with CO2 and H2O on the right side.

So B is the answer.

You're not doing anything to paper if you shred it except make it smaller. It retains all of its chemical properties and almost all its physical properties.

Ice melting doesn't do anything to the water when it changes phase except you now have a puddle on the table where the ice (cube) was. But you are still dealing with water.

Metal foil is heated, again the foil is left with all its chemical properties in tact. You can reuse the foil if you are cooking potatoes in an open fire. Nothing has altered the chemical properties of the foil.

Iteru [2.4K]3 years ago

6 0

The answer is when GAS IS BURNED because when gas is burned, it cannot return into its previous state. Also, new substances are formed.

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What is the amount of displacement of a runner who runs exactly 2 laps around a 400 meter track?

Alex787 [66]

Displacement is the distance and direction from the start point to the end point. Our runner finished exactly where he started. His displacement is zero.

5 0

3 years ago

Read 2 more answers

A balloon is expanded to the same volume as that of a human head. Do an order-of-magnitude estimate of the volume of this balloo

cestrela7 [59]

Answer:

Volume of balloon = 1000 cm^3

Explanation:

The head of a normal person can be assumed as a sphere with radius 10 cm.

Volume of sphere $=\frac{4}{3} \pi r^3$ , where r is the radius.

We have approximate radius = 10 cm.

Approximate volume of head $=\frac{4}{3} \pi r^3=\frac{4}{3} *\pi* 10^3=4188cm^3$

In the given options the closest value to the approximate volume is 1000 cm^3.

So, volume of head = Volume of balloon = 1000 cm^3

4 0

3 years ago

If the absolute pressure of a gas is 550.280 kPa, its gage pressure is A. 101.325 kPa. B. 651.605 kPa. C. 448.955 kPa. D. 277.28

guajiro [1.7K]

Answer:

Option C is the correct answer.

Explanation:

Absolute pressure is sum of gauge pressure and atmospheric pressure.

That is

$P_{abs}=P_{gauge}+P_{atm}$

We have

$P_{abs}=550.280 kPa\\\\P_{atm}=1atm=101325Pa=101.325kPa$

Substituting

$P_{abs}=P_{gauge}+P_{atm}\\\\550.280=P_{gauge}+101.325\\\\P_{gauge}=448.955kPa$

Option C is the correct answer.

7 0

3 years ago

The gravitational attraction between two objects increases if

JulijaS [17]

Answer:

they are closer!!

Explanation:

Hope this helped!! :D

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3 years ago

Explain electric circuits. Be sure to include the features, the roles, and the types. Help PLEASEEEE!!

maksim [4K]

If there was any way to do that, then your teacher wouldn't
need to keep you coming into class every day and doing
homework every night. She could just give you the 3 or 4
paragraphs and a few pictures that you're asking me for,
and bada-bing ! you'd know it !

The time it takes, and the amount of homework it takes, is
EXACTLY the time you spent hearing about it in class.

(Unless you're some kind of genius savant prodigy, which
you're not and I'm not.)

5 0

3 years ago