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Earth climate has stayed same thougout the past

Explanation:

Explanation: It's a 3.0 M solution so 1 litre of solution contains 3 moles of NaOH. 250 ml of solution therefore contains 0.25 x 3 = 0.75 moles of NaOH. The molar mass of NaOH is 39.9971 g/mol, so 250 ml of this solution contains 0.75 x 39.9971 = 29.99 g, or if you round it up 30.0 g.

30g of NaOH is in 250 mL of a 3.0M NaOH solution​.

The mole is an amount unit similar to familiar units like pair, dozen, gross, etc. It provides a specific measure of the number of atoms or molecules in a bulk sample of matter.

A mole is defined as the amount of substance containing the same number of atoms, molecules, ions, etc. as the number of atoms in a sample of pure 12C weighing exactly 12 g.

Given,

Volume of NaOH = 250 ml

Concentration = 3M

number of moles = concentration × volume (L)

= 3 × 0.25

= 0.75 moles

mass = moles × molar mass

= 0.75 × 40

= 30 g

Therefore, 30g of NaOH is in 250 mL of a 3.0M NaOH solution​.

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Answer: Yes, light can bend around corners. ... The ability of light to bend around corners is also known as "diffraction". There are two mechanisms that cause light to bend around corners. Light waves indeed bend around corners because of diffraction, as shown in this illustration.

Explanation:

In a dry cell the electrolyte is a paste.

Minerals with an electric charge called electrolytes could be found in human blood and other bodily fluids. Electrolytes have a variety of effects on how your brains work, including how much water is in your body. The pH balance in the blood (pH) Our muscles work.

The dry-cell battery would be a gadget composed of one or even more electrochemical cells which change electrical energy from chemical energy that has been stored. It has an electrolyte inside of a paste or another moist substance. Zinc anode, as well as carbon cathode, are found inside a central rod of a standard dry cell battery.

Therefore, in a dry cell the electrolyte is a paste.

Hence, the correct answer will be option (B).

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Answer:

666.93 kJ

Explanation:

Using the formula;

Q = m × c × ∆T

Where;

Q = amount of heat absorbed (Joules)

m = mass of substance (g)

c = specific heat capacity (4.184 J/g°C)

∆T = change in temperature (°C)

Based on the information provided in the question;

Q = ?

m = 2000g

∆T = 99.7 °C - 20 °C = 79.7 °C

c = 4.184 J/g°C

Using Q = m × c × ∆T

Q = 2000 × 4.184 × 79.7

Q = 666929.6 Joules

To calculate the amount of heat absorbed (Q) in kilojoules (kJ), we say;

1 joule = 0.001 kilojoule

666929.6 Joules = 666929.6 × 0.001

= 666.9296 KJ

Approximately, Q = 666.93 kJ.

Answer:

B

Explanation:

Answer:

Electrons in atoms occupy energy levels, also called electron shells, outside the nucleus . Different shells can hold different maximum numbers of electrons. The electrons in an atom occupy the lowest available energy level first. This is the shell nearest the nucleus.

Explanation:

Answer:

[tex]\boxed {\boxed {\sf 129.267 \ g \ C_6H_{14}}}[/tex]

Explanation:

To convert from moles to mass, the molar mass is used. This is the grams per mole for a substance.

The values are found on the Periodic Table. They are the same as the atomic masses, but the units are grams per mole instead.

We are given this compound: C₆H₁₄. Look up the molar masses for the individual elements first: carbon and hydrogen.

Check the subscripts, which tell us the number of atoms per molecule.  There are 6 carbon atoms and 14 hydrogen atoms. Multiply the molar mass by that number, then add them together.

Use the molar mass as a ratio.

[tex]\frac {86.178 \ g \ C_6H_{14}}{1 \ mol \ C_6H_{14}}}[/tex]

Multiply by 1.5 moles.

[tex]1.5 \ mol \ C_6H_{14} \times \frac {86.178 \ g \ C_6H_{14}}{1 \ mol \ C_6H_{14}}}[/tex]

The moles of C₆H₁₄ will cancel each other out.

[tex]1.5 \times \frac {86.178 \ g \ C_6H_{14}}{1}}[/tex]

[tex]1.5 \times {86.178 \ g \ C_6H_{14}}[/tex]

[tex]129.267 \ g \ C_6H_{14}[/tex]

1.5 moles of C₆H₁₄ is equal to 129.267 grams of C₆H₁₄

Answer:

P waves travel faster than other waves

Explanation:

P waves travel fastest and are the first to arrive from the earthquake. In S or shear waves, rock oscillates perpendicular to the direction of wave propagation. In rock, S waves generally travel about 60% the speed of P waves, and the S wave always arrives after the P wave.

Answer:

Explanation:

Option C is the correct answer

Among electromagnetic waves, UV rays are most dangerous because exposure to these radiation cause serious problems in living organism. Therefore, the correct option is option C.

Electromagnetic wave is a wave which contain two component one is electric component and other is magnetic component. The electric and magnetic component are perpendicular to each other. There are so many wave that comes under electromagnetic wave like infrared wave , radio wave.

There is a relation between energy of wave. frequency of wave, and wavelength of wave

Mathematically,

E=hc/λ

where,

E = energy of electromagnetic wave

h is planks constant having value 6.67×10⁻³⁴js

c is speed of light that is 3×10⁸m/s

λ is the wavelength of electromagnetic wave

An electromagnetic spectrum refer to a range of wavelengths of light that increases from one end to the other.

Therefore, the correct option is option C.

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Answer:

Selenium Dioxide: Se[tex]O_{2}[/tex]

Explanation:

This is a compound that contains both Selenium and Oxygen.

Answer:

Hi ,

Answer:

A chemical energy is changed to a electrical energy

Answer:

Explanation: The goal of every country should be to produce more materials and goods

Explanation:

a.Silver chloride

b.zinc Oxide

c.calcium Bromide

d.strontium difluoride

Answer:

Option B, In a space-filling model of a molecule, the radii of the spheres in a space-filling model are proportional in size to the radii of the atoms

they represent

Explanation:

In a space-filling model of a molecule, atoms are represented as sphere. The radius of the sphere is equal to the radius of the atom and the distance between the center of one sphere to the center of other represents the distance between the atomic nuclei

Option B is correct

Option A is incorrect, as dots are used in the space filling model to represent the atoms

Option C is incorrect because radii of atom do not represents the length of the bonds in a space-  filling model

Answer:

B

Explanation:

Generally, when you dilute something, your goal is to thin your concentration. Even if you added a solute, if your goal is dilution, it will make the concentration decrease.

Answer:

Answer:

Heeeeeeeeeeeeeloooooooooo

Explanation:

Explanation:

6. Which type mixture does not allow light to shine through?

D) Suspensions

10. What is a closed system in chemical equilibrium?

Solution:

-TheUnknownScientist

Answer:

For an electron they start at the first level (n=1) In order to move up to the next level (n=2) the amount of quantom energy to move to this next level the energy must be perfect in order to move. If the quantom energy is to small the electron it doesn't try.

Answer:

Scientist 3

Explanation:

Answer:

b

Explanation:

Answer:

Lungs.

Explanation:

They bring the blood throughout the body, to help it function properly

Answer:

1. 10

Explanation

when litmus paper is blue that means the solution is basic and 10 on the pH scale is the most basic out of all your options

Bonjour!

At all four positions, the northern end of Earth's axis points towards the Polaris. I will enter a diagram below to help you visualize!

Au revoir, hope this helped you!

Sincerely- frenchsmartie

Answer:

it's about changing attitudes and behavior.

Answer:

yes I know it.

Explanation:

A:positive terminal

B:cathode

C:electrolyte

D:anode

E:negative terminal

Thank you for this question

Answer:

The daily change from daylight to darkness is caused by:the rotation of the Earth on its axis. If the Earth did not rotate as it does, the day/night cycle would be very different or possibly even nonexistent.

Explanation:

Answer:

i believe the answer is b

Explanation:

a gradual increase in the overall temperature of the earth's atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide, chlorofluorocarbons, and other pollutants.