NEED HELPPP PLSSSSSSSSSS

Answer:

B the density stays the same

Answer:

1 mole Of Helium = Weight of Helium/4Weight of Helium = 1*4 = 4 grams 1 mole of Helium contains 6.023*10²³ ( Avogadro number) atoms. Number of moles of in 4 grams of Hydrogen 4 grams is = given weight / molecular weight of Hydrogen (H₂) = 4/2 =2 Number of atoms/molecules in 2 moles of Hydrogen is (2*6.023*10²³) atoms. = 12.046*10²³ atoms.

(Hope this helps)

The number of atoms in 2 moles of helium is 1.204×10²⁴ atoms

From Avogadro's hypothesis,

1 mole of any substance = 6.02×10²³ atoms

Thus,

1 mole of helium = 6.02×10²³ atoms

With the above information in mind, we can obtain the number of atoms in 2 moles of helium as follow:

1 mole of helium = 6.02×10²³ atoms

Therefore,

2 moles of helium = 2 × 6.02×10²³ atoms

2 moles of helium = 1.204×10²⁴ atoms

Thus, we can conclude that 2 moles of helium contains 1.204×10²⁴ atoms

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sound energy, kinetic energy,

i cant think of any more but hope this helps

Answer:

Mechanical to kinetic to sound to heat

Explanation:

Remember that all types of energy transformation end in heat

Answer:

0.03

Explanation:

22.8 g Ba(OH)2 (1 mol Ba (OH)2/ 171.34 g) = 0.133 mol Ba (OH)2

77.2 g H2O (1 mol H2O/18 g) = 4.29 mol H2O

X= molar fraction= mol Ba(OH)2/ mol total

X= 0.133/ (0.133+4.29) = 0.03

0.03 is the mole fraction of [tex]Ba(OH)_2[/tex] in an aqueous solution that contains 22.8% [tex]Ba(OH)_2[/tex] by mass.

The ratio of the number of moles of one component of a solution or other mixture to the total number of moles representing all of the components.

Moles of [tex]Ba(OH)_2[/tex]

Moles = [tex]\frac{mass}{molar \;mass}[/tex]

Moles = [tex]\frac{22.8 g Ba(OH)_2}{171.34 g}[/tex]

= 0.133 mol [tex]Ba (OH)_2[/tex]

Moles of [tex]H_2O[/tex]

[tex]Moles = \frac{mass}{molar \;mass}[/tex]

[tex]Moles = \frac{77.2 g H_2O}{18 g}[/tex]

= 4.29 mol [tex]H_2O[/tex]

The mole fraction of [tex]Ba(OH)_2[/tex]

[tex]\frac{mol Ba(OH)_2}{total \;mol}[/tex]

= 0.03

0.03 is the mole fraction of [tex]Ba(OH)_2[/tex] in an aqueous solution that contains 22.8% [tex]Ba(OH)_2[/tex] by mass.

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Answer:

The Sun powers life on Earth; it helps keep the planet warm enough for us to survive. It also influences Earth’s climate: We know subtle changes in Earth’s orbit around the Sun are responsible for the comings and goings of the past ice ages. But the warming we’ve seen over the last few decades is too rapid to be linked to changes in Earth’s orbit, and too large to be caused by solar activity

Explanation:

Answer:

Should be A

Explanation:

Answer:

Dark matter also called baronic matter is the matter that makes up 27% of the universe.

In 1933 it was determined as that mass that cannot be seen, that is, the non-visible mass of outer space.

Dark matter also plays a central role in the formation of structures and the evolution of galaxies and has measurable effects on the anisotropy of cosmic microwave background radiation. The composition of this matter is unknown today.

The dark matter component has considerably more mass than the "visible" component of the Universe.

Explanation:

There are certain researchers who say that the appearance of dark matter was before the appearance of the big bang.

A relevant fact of this matter is that dark matter exerts gravity, and that gravity affects the movements of objects.

Despite the fact that nothing is known about its origin, astronomers have amply demonstrated that dark matter plays a determining role in the formation of galaxies and galactic clusters, which could not maintain their cohesion without its existence, but many doubt that it is the remainder / remnant or product of a big bang.

Answer:

Water, and other neutral

Explanation:

That means those substances have pH = 7.

When the amount of H+ is more than the amount of OH- in solution, the substance is acidic ( eg.: Lemon juice ). pH < 7

When the amount of H+ is less than the amount of OH- in solution, the substance is basic ( eg.: Baking soda ). pH > 7

Answer:

unbalanced

Explanation:

Cl and H have an extra atom

- Hope that helps! Please let me know if you need further explanation.

Answer:

c

Explanation:

Answer:

Li has fewer protons than Li+

Answer:

55×10^-26 J

Explanation:

We can calculate the energy of the wave from

E= hc/λ

Where

h= Planks constant = 6.6×10^-34 Is

c= speed of light = 3×10^8 ms-1

λ= wavelength of the wave = 0.36 metres

Recall that cell phone use radio waves which belong to the electromagnetic spectrum hence it must possess the speed of light.

E= 6.6×10^-34 × 3×10^8/ 0.36

E= 55×10^-26 J

Hence the energy possessed by 0.36 meters wavelength radio waves is 55×10^-26 J

Answer:

Gamma Rays.

Explanation:

Gamma-ray photons have the highest energy in the EMR spectrum and their waves have the shortest wavelength.

Answer:

Heat energy (Q) = 1.9925 KJ = 2 KJ (Approx)

Explanation:

Given:

Mass of copper (M) = 45 gram

Change in temperature (ΔT) = 71°C - 12°C = 59°C

Specific heat (c) =0.75 j /g*c

Find:

Heat energy (Q) = ?

Computation:

Heat energy (Q) = Mass(M) × Change in temperature (ΔT) × Specific heat (c)

Heat energy (Q) = 45 gram × 59°C × 0.75 j /g*c

Heat energy (Q) = 1991.25 J

Heat energy (Q) = 1.9925 KJ = 2 KJ (Approx)

Answer:

C

Explanation:

The answer is always C

Answer:C. Concave mirror

Explanation:

When the surface of a mirror curves inward, like the inside of a bowl, it is called c. Concave mirror.

Answer:

CH3−CO−O−CH3

Explanation:

i just took the test

Hey there!

P₄ + Cl₂ → PCl₃

First, let's balance Cl.

There are 2 on the left, and 3 on the right.

To balance this, let's put a coefficient of 3 in front of Cl₂ and a coefficient of 2 in front of PCl₃.

P₄ + 3Cl₂ → 2PCl₃

Now we have 6 on the left and 6 on the right.

Next, let's balance P.

There are 4 on the left and 2 on the right.

Let's change the coefficient in front of PCl₃ from 2 to 4.

P₄ + 3Cl₂ → 4PCl₃

There are now 4 P on each side.

However, now Cl is unbalanced, with 6 on the left and 12 on the right.

We can change the coefficient in front of Cl₂ from 3 to 6.

P₄ + 6Cl₂ → 4PCl₃

So now, we have 4 P on each side and 12 C on each side.

This is our final balanced equation.

Hope this helps!

Answer:

1:1

Explanation:

Took test

Answer:

True!

Explanation:

Fossil fuels are carbon based compounds present deep in the earth left millions of years ago.

hope it helps!

Answer:

2.078x10^24

Explanation:

No. of atoms of chlorine = 3.45 x 6.022x 10 ^23 x 1

= 2.078x10^24

( to find no. of atoms of, heres the formula i was taught No. of atoms = no. of moles x Avogadros constant x no. of atoms in the formula of compound)

Answer:

Volume = 5.73L

Explanation:

Data;

V1 = 3.75L

P1 = 0.980atm

P2 = 0.641atm

V2 = ?

This question involves the use of Boyle's law, which states that, the volume of a fixed mass of gas is inversely proportional to its pressure provided that temperature remains constant.

Mathematically,

V = kP, k = PV

P1V1 = P2V2 =P3V3=........=PnVn

P1V1 = P2V2

V2 = (P1 * V1) / P2

V2 = (0.980 × 3.75) / 0.641

V2 = 5.73L

The final volume of the gas is 5.73L

Answer:

0 °C and 1 Atm,

Explanation:

Standard Temperature and Pressure. Standard temperature is equal to 0 °C, which is 273.15 K.

Standard Pressure is 1 Atm, 101.3kPa or 760 mmHg or torr

"Typical nonmetals have a dull, coloured or colourless appearance; are brittle when solid; are poor conductors of heat and electricity; and have acidic oxides." - Wikipedia

Answer:

Explanation:

Soap breaks up the oil into smaller drops, which can mix with the water. It works because soap is made up of molecules with two very different ends. One end of soap molecules love water - they are hydrophilic. The other end of soap molecues hate water - they are hydrophobic.

Answer:

C. Its polar end mixes with the water so it can be washed away.

Explanation:

Just took test

Answer:

answer: A. all of the living organisms in a specific place at a specific time

Explanation:

Answer:

b

Explanation:

Electromagnetic waves are waves that have no medium to travel whereas mechanical waves need a medium for its transmission.

Answer:

el nino: the boy

la nina: the girl

Explanation:

Answer:

el nino is dinosour la nino is fishcat

Explanation:

Answer:

4.92 L

Explanation:

Rearrange ideal gas law and solve.

Change C to K.

- Hope that helps! Please let me know if you need further explanation.

Answer:

increases

Explanation:

As the temperature of a fixed volume of a gas increases, the pressure will increase.

According to this law at constant volume of gas, pressure is directly proportional to the temperature of the gas and it is represented as:

P ∝ T.

It means that if pressure increases then temperature is also increases or if pressure decreases then temperature will also decreases.

So, pressure of the gas increases.

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Answer: Volume =  50.0 mL in liters : 50.0 / 1000 = 0.05 L

n = M x V

n = 0.20 x 0.05

n = 0.01 moles of solute

Explanation:

The number of moles of solute are present in 50.0 mL of 0.20 M of KNO₃ solution is 0.01 moles.

Moles will be calculated by using the molarity formula because molarity is define as the no. of moles of solute present in per liter of the solution as:

M = n/V, where

M = molarity of KNO₃ = 0.2 M

V = volume of solution = 50mL = 0.05L

Moles will be calculated as:

n = (0.2)(0.05) = 0.01 moles

Hence required moles are 0.01 moles.

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