The total amount of energy before and after a chemical reaction is the same. Therefore, energy is _____.
created

destroyed

converted

conserved

Answer:

A. They contain older stars and less gas and dust.

Explanation:

There are three types of galaxies:

Elliptical galaxies are galaxies shaped like an ellipse, while spiral galaxies consist of a flat, rotating disk that contains stars, gas, and dust, and a central concentration of stars called the bulge.

The difference between elliptical and spiral galaxies is in the amount of gas and dust they contain. Spiral galaxies contain large amounts of gas and dust, which means that new stars are born very often. This makes them brighter than relatively dim elliptical galaxies, which contain less gas and dust. This is why fewer new and brighter stars are born in elliptical galaxies, leaving them with older, dimmer stars.

Answer:

C

Explanation:

Li has an electronegativity of 0.98, O has an electronegativity of 3.44. 3.44-0.98= 2.46 electronegativity differnece :)

Answer:

m(Ag) = 227.5g

Explanation:

...what is the mass of the piece of silver?

The heat given for the piece of silver is the same heat that is absorbed for the water, that is:

m(Ag)×C(Ag)×ΔT(Ag) = m(Water)×C(Water)×ΔT(Water)

m is mass of water in solution: 26.0mL = 26g of water

And m(Ag) is the mass of Ag, our incognite.

C is specific heat (0.240J/g°C for Ag), and 4.184J/g°C for water

ΔT is change in temperature (93.8°C - 44°C = 49.8°C) for Ag ad (44°C - 19°C = 25°C)

Replacing:

m(Ag)×C(Ag)×ΔT(Ag) = m(Water)×C(Water)×ΔT(Water)

m(Ag)×0.240J/g°C×49.8°C = 26g×4.184J/g°C×25°C

m(Ag)* 11.952J/g = 2719.6J

Answer:

a. 4.865 × 10⁻⁷ molecules. b. The possible health benefits of the drug might be minimal or non-existent.

Explanation:

a. Since we have 0.10 mol/L and 10 mL of solution, the number of moles in 10 mL of solution is n = CV where C = concentration and V = Volume. C = 0.10 mol/L and V = 10 mL = 0.01 L.

So n = CV = 0.10 mol/L × 0.01 L = 0.001 mol.

Since the initial volume of the solution is 10 mL and doubled, it is 2 × 10 mL = 20 mL. It is doubled again to 2 × 20 mL = 40 mL. It is doubled again to 2 × 40 mL = 80 mL. Our third doubling is thus 80 mL = 2 × 2 × 2 × 10 mL = 2³ × 10 mL. So the volume for our nth doubling is V = 2ⁿ × 10 mL. So four our 90 th doubling, the volume is V = 2⁹⁰ × 10 mL = 2⁹⁰ × 10 mL

Since we have 0.001 mol present, the concentration in this new volume is thus C' = 0.001 mol/2⁹⁰ × 10 mL.

So the number of moles in 10 mL of this solution is thus n = 0.001 mol/(2⁹⁰ × 10 mL) × 10 mL = 0.001/2⁹⁰ mol

To find the number of molecules of X present we use, number of moles, n = number of molecules, N/Avogadro's number of molecules, N'

n = N/N'

N = nN'

= 0.001/2⁹⁰ mol × 6.022 × 10²³ molecules/mol

= 8.078 × 10⁻³¹ × 6.022 × 10²³

= 48.65 × 10⁻⁸

= 4.865 × 10⁻⁷ molecules.

b. Since the number of molecules of X present in 10 mL solution of the final diluted solution is 4.865 × 10⁻⁷ molecules, this shows that the number of molecules of X is very little so, the possible health benefits of the drug might be minimal or non-existent.

true

Explanation:

Ecothermic reactiions are reactions or processes that release energy. From heat or light.

A.True

Explanation:

Reactants+Products+Energy

Explanation:

this question was answered in a couple weeks with the same question I did u do not want me and my dad did it all over and u just said it is not going well and you don't want me and my mom and dad don't mind if I can come up to the mall and pick them out on my own and I can come

Answer:

pure substance

Explanation:

it is a naturally occuring compound

Answer:

Formaldehyde is a mixed substance. It is made up of Carbon, 2 Hydrogen, and an Oxygen.

Explanation:

The formula is CH2O

Answer:

the 2 means there are 2 al and the 3 means there are 3 o

Explanation:

I hope this helps

Explanation:

Molar mass of Ba(NO3)2 = 261.3368 g/mol

Answer:

we know, at STP ( standard temperature and pressure).

we know, volume of 1 mole of gas = 22.4L

weight of 1 Litre of hydrogen gas = 0.09g

so, weight of 22.4 litres of hydrogen gas = 22.4 × 0.09 = 2.016g ≈ 2g = molecular weight of hydrogen gas.

similarly,

weight of 2L of a gas = 2.88gm

so, weight of 22.4 L of the gas = 2.88 × 22.4/2 = 2.88 × 11.2 = 32.256g

hence, molecular weight of the gas = 32.256g

vapor density = molecular weight/2

= 32.256/2 = 16.128g

hence, vapor density of the gas is 16.128g.

Explanation:

Answer: Many argue that modern chemical science began when scientists started ... Figure 3.2 The average mass of a chloroform molecule, CHCl3, ... 5.00gCu(molCu63.55g)(6.022×1023atomsmol)=4.74×1022atoms of copper

Explanation: hope this helps

Answer:

what are you asking tho?

Explanation:

Thx for the Free points tho.

Answer:

68000J/kg

Explanation:

Given parameters:

 Mass of the substance  = 0.5kg

 Quantity of heat transferred to the body  = 34000J

Unknown:

Specific latent heat of fusion = ?

Solution:

The specific latent heat is usually involve in phase changes;

  H  = mL

H is the quantity of heat supplied

m is the mass

L is the specific latent heat

 Insert the parameters and solve;

     34000 = 0.5 x L

         L  = [tex]\frac{34000}{0.5}[/tex]   = 68000J/kg

Answer:

NH4

Explanation:

Answer:

An object that is at rest will stay at rest unless a force acts upon it. An object that is in motion will not change its velocity unless a force acts upon it. This is known as uniform motion. An object continues to do whatever it happens to be doing unless a force is exerted upon it.

Explanation: NEWTONS laws of motion

Answer:

Lithosphere plate boundaries are found in that area.

Explanation:

Answer:

C is the right answer

Explanation:

B. It dissolves in water.

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Answer:

B it dissolves in water

Explanation:

Their molecules bond to water molecules

Answer:

Try searching this on google

Explanation:

I might have an answer but I am not entirely sure sorry I really tried to help but there is also an app called socractic it also helps with questions

Once the temperature reaches 15,000,000 levels Celsius, nuclear fusion takes location in the center, or core, of the cloud. The high-quality heat given off by means of the nuclear fusion technique motives the gasoline to glow creating a protostar. This is the first step in the evolution of a star.

Answer:

b:   Neither atoms will have a full valence shell

Explanation:

I think sooo

Answer:

Explanation:

The mass of an object can be found by using the formula

[tex]m = \frac{f}{a} \\ [/tex]

f is the force

a is the acceleration

From the question we have

[tex]m = \frac{18}{5.8} \\ = 3.103448...[/tex]

We have the final answer as

Hope this helps you

Answer:

i think it would be 35

Explanation:

r

Answer:

The color of the light emitted depends on the energies of the photons emitted, which are in turn are determined by the energies required to move electrons from one orbital to another. Those colors are as distinctive to each element as fingerprints are to people. Hope this helps

Answer:

The color of the light emitted depends on the energies of the photons emitted, which are in turn are determined by the energies required to move electrons from one orbital to another. Depending on the element you put in the flame, various different energies of photons (colors) will appear. Those colors are as distinctive to each element as fingerprints are to people.

Explanation:

Answer:

Yes it is true reaction

Answer: yes it is true

Explanation: i took the test

Answer:

Polling is a method used for the purification of copper or tin which contains oxide impurities

Answer:

Polling is used for the purification of copper or tin which contains oxide impurities. The impure metal is melted and stirred with green logs of wood. The heat of molten metal makes the green logs to liberate hydrocarbon gases which in turn reduce the metal oxide into metal.