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3 years ago

10

What happens in a chemical change that does not occur in a physical change?

1 answer:

Andrej [43]3 years ago

6 0

Answer:

In a chemical reaction, there is a change in the composition of the substances in question; in a physical change there is a difference in the appearance, smell, or simple display of a sample of matter without a change in composition. Although we call them physical "reactions," no reaction is actually occurring.

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Sort each characteristic according to whether it describes acid, bases, or both.

VARVARA [1.3K]

Answer:

Acids: react with metals, taste sour

Both: can cause burns, conduct electricity

Basis: react with nonmetals, taste bitter

Explanation:

This is the right answer

4 0

3 years ago

What is the wavelength in picometers for an electron with 360 eV of kinetic energy?

Rom4ik [11]

Answer:

Wavelength = 64.635 pm

Explanation:

The expression for the deBroglie wavelength and kinetic energy is:

$\lambda=\frac {h}{\sqrt{2\times m\times K.E.}}$

Where,

$\lambda$ is the deBroglie wavelength

h is Plank's constant having value $6.626\times 10^{-34}\ Js$

m is the mass of electron having value $9.11\times 10^{-31}\ kg$

K.E. is the kinetic energy of the electron.

Given, K.E. = 360 eV

Energy in eV can be converted to energy in J as:

1 eV = 1.6022 × 10⁻¹⁹ J

So, K.E. = $360\times 1.6022\times 10^{-19}\ J=5.76792\times 10^{-17}\ J$

Applying in the equation as:

$\lambda=\frac {h}{\sqrt{2\times m\times K.E.}}$

$\lambda=\frac{6.626\times 10^{-34}}{\sqrt {{2\times 9.11\times 10^{-31}\times 5.76792\times 10^{-17}}}}\ m$

$\lambda=\frac{10^{-34}\times \:6.626}{\sqrt{10^{-48}\times \:105.0915024}}\ m$

$\lambda=6.4635\times 10^{-11}\ m$

Also, 1 m = 10¹² pm

<u>So, Wavelength = 64.635 pm</u>

4 0

4 years ago

Please answer quick!!!

kherson [118]

Answer:

neurotransmitter

Explanation:

im 200 iq

6 0

3 years ago

A compound composed of only c and f contains 17.39 c by mass. what is its empirical formula

Ostrovityanka [42]

Since the Carbon C is 17.39% by mass hence the Fluorine F is 82.61% by mass. Divide each mass % by the respective molar masses, that is:

C = 17.39 / 12 = 1.45

F = 82.61 / 19 = 4.35

Divide the two by the smaller number, so divide by 1.45

C = 1.45 / 1.45 = 1

F = 4.35 / 1.45 = 3

So the empirical formula is:

CF3

4 0

3 years ago

Which is used to convert between mass and moles of a substance?

sveticcg [70]

The molar mass constant is used to convert mass to moles

3 0

3 years ago