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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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Psuedopod in a sentence

mixas84 [53]

Does it have to be that exact word. cause it is just another term for psuedopodium

5 0

3 years ago

The moon's mass is 7.34x10-kg and it is 3.8x10m away from earth. Calculate the gravitational force of attraction between earth a

Nana76 [90]

Again I think you did not give the right constants. So I would use the correct constants for mass of moon and distance from earth to moon.

The formula for force of attraction between any two bodies in the universe
F = GMm / r^2. (Newton's Universal law of Gravitation).

G = Universal gravitational constant, G = 6.67 * 10 ^ -11 Nm^2 / kg^2.
M = Mass of Earth. = 5.97 x 10^24 kg.
m = mass of moon = 7.34 x 10^22 kg.
r = distance apart, between centers = in this case it is the distance from Earth to the Moon
= 3.8 x 10^8 m.

(Sorry I could not assume with the values you gave, they are wrong, and if we use them we would be insulting Physics).

So F = ((6.67 * 10 ^ -11)*(5.97 x 10^24)*(7.34 * 10^22)) / (3.8 x 10^8)^2.
Punch it all up in your calculator.

I used a Casio 991 calculator, it should be one of the best in the world.Really lovely calculator, that has helped me a lot in computations like this. I am thankful for the Calculator.

F = 2.0240 * 10^ 20 N.
So that's our answer.
Hurray!!

8 0

3 years ago

Read 2 more answers

A proton, an electron, and a helium nucleus all move at speed v . Rank their de Broglie wavelengths from largest to smallest.

Varvara68 [4.7K]

Ranking of de Broglie wavelengths from largest to smallest is electron > proton > helium

De Broglie proposed that because light has both wave and particle properties, matter exhibits both wave and particle properties. This property has been explained as the dual behavior of matter.
From his observations, de Broglie derived the relationship between the wavelength and momentum of matter. This relationship is known as de Broglie's relationship

De Broglie's relationship is given by $\lambda=\frac{h}{mv}$ .....(1) , where λ is known as de Broglie wavelength and m is mass , v is velocity , h = Plank’s constant.

From equation (1) wavelength and mass has an inverse relation .

Mass of helium is 4 times the mass of the proton and proton has a greater mass than electron.

According to equation (1) , less the mass higher will be the wavelength

Hence electron having less mass have higher wavelength and then proton and then helium having large mass will have less wavelength .

Thus, order should be electron > proton > helium .

Learn about de brogile wavelength more here :

brainly.com/question/16595523

#SPJ4

8 0

1 year ago

A cat is moving at 18 m/s when it accelerates for 2 seconds. What is its acceleration?

vova2212 [387]

Answer: acceleration: $4 m/s^{2}$

velocity: $26 m/s$

Explanation:

The complete question is written bellow:

A cat is moving at 18 m/s when it accelerates at $4 m/s^{2}$ for 2 seconds. What is his new velocity?

In this situation the following equation will be useful:

$V=V_{o}+at$

Where:

$V$ is the cat’s final velocity (new velocity)

$V_{o}=18 m/s$ is the cat’s initial velocity

$a=4 m/s^{2}$ is the cat's acceleration

$t=2 s$ is the time

Solving the equation:

$V=18 m/s+(4 m/s^{2})(2 s)$

$V=26 m/s$ This is the cat's new velocity

5 0

3 years ago

Can someone solve this problem and explain to me how you got it

Zarrin [17]

1) The electric force changes by a factor of 25

2) The electric force changes by a factor of 16/9

Explanation:

The magnitude of the electrostatic force between two charges is given by Coulomb's law:

$F=k\frac{q_1 q_2}{r^2}$

where:

$k=8.99\cdot 10^9 Nm^{-2}C^{-2}$ is the Coulomb's constant

$q_1, q_2$ are the two charges

r is the separation between the two charges

In this problem, let's call F the initial force between the two charges when they are at a distance of r.

Later, the distance is changed by a factor of 5. Let's assume it has been increased to a factor of 5: so the new distance is

r' = 5r

Therefore, the new force between the charges is:

$F' = k' \frac{q_1 q_2}{r'^2}=k' \frac{q_1 q_2}{(5r)^2}=\frac{1}{25}(k' \frac{q_1 q_2}{r'^2})=\frac{F}{25}$

So, the force has changed by a factor of 25.

The original force between the two charges is

$F=k\frac{q_1 q_2}{r^2}$

In this problem, we have:

- The distance between the charges is changed by a factor of 6:

r' = 6r

- The charges are both changed by a factor of 8:

$q_1' = 8q_1$

$q_2' = 8q_2$

Substituting into the equation, we find the new force:

$F' = k' \frac{q_1' q_2'}{r'^2}=k' \frac{(8q_1) (8q_2)}{(6r)^2}=\frac{64}{36}(k' \frac{q_1 q_2}{r'^2})=\frac{16}{9}F$

So, the force has changed by a factor of 16/9.

Learn more about electric force:

brainly.com/question/8960054

brainly.com/question/4273177

#LearnwithBrainly

6 0

3 years ago