What keeps galaxies togther? How?

Answers

Answer 1
Tough question, I would suggest using Google maybe, or just plain out asking your science teacher.

Related Questions

30.1 grams of ice at -250^oC would be required how many kj to increase it's temperature to 15.0^ᴏC

Answers

Answer:

16.1923 kj

Explanation:

Given data:

Mass of ice = 30.1 g

Initial temperature = -250 °C

Final temperature = 15.0 °C

Energy required = ?

Solution:

Specific heat capacity of ice is 2.03 J/g.°C

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT  = 15.0°C - (-250 °C)

ΔT  = 265°C

Q = 30.1 g × 2.03 J/g.°C × 265°C

Q = 16192.3 J

J to kJ:

16192.3 J × 1 KJ /1000 j

16.1923 kj

2) Why do transition elements show variable
oxidation states

Answers

Answer:

These elements show variable oxidation state because their valence electrons in two different sets of orbitals, that is (n-1)d and ns. The energy difference between these orbitals is very less, so both the energy levels can be used for bond formation. Thus, transition elements have variable oxidation states

Transition elements show variable state oxidation in their compounds because there is a very small energy difference in between (n-1)d and ns orbitals. As a result, electrons of (n-1)d orbitals as well as ns-orbitals take part in bond formation.

A sample of carbon dioxide is contained in a 250.0 mL flask at 0.917 atm and 19.3 ∘ C. How many molecules of gas are in the sample?

Answers

Answer:

The correct answer is 5.76 x 10²¹ molecules

Explanation:

From the problem, we have the following data:

V= 250.0 mL = 0.25 L

P= 0.917 atm

T= 19.3∘C + 273 = 292.3 K

We can use the ideal gas law to find n (number of moles of gas):

PV= nRT

⇒ n = PV/RT = (0.917 atm x 0.25 L)/(0.082 L.atm/K.mol x 292.3 K) = 9.6 x 10⁻³ mol

We know that 1 mol of any compound is equal to 6.022 x 10²³ molecules of the compound⇒ ratio : 6.022 x 10²³ molecules/1 mol

Thus, we multiply n by the ratio to obtain the number of molecules of gas:

9.6 x 10⁻³ mol x 6.022 x 10²³ molecules/1 mol = 5.76 x 10²¹ molecules

The specific heat of liquid bromine is 0.226 J/g-K. How much heat (J) is required to raise the temperature of 10.0 mL of bromine from 25.00 °C to 27.30 °C? The density of liquid bromine: 3.12 g/mL

Answers

Answer:

16.2 J

Explanation:

Step 1: Given data

Specific heat of liquid bromine (c): 0.226 J/g.KVolume of bromine (V): 10.0 mLInitial temperature: 25.00 °CFinal temperature: 27.30 °CDensity of bromine (ρ): 3.12 g/mL

Step 2: Calculate the mass of bromine

The density is equal to the mass divided by the volume.

ρ = m/V

m = ρ × V

m = 3.12 g/mL × 10.0 mL

m = 31.2 g

Step 3: Calculate the change in the temperature (ΔT)

ΔT = 27.30 °C - 25.00 °C = 2.30 °C

The change in the temperature on the Celsius scale is equal to the change in the temperature on the Kelvin scale. Then, 2.30 °C = 2.30 K.

Step 4: Calculate the heat required (Q) to raise the temperature of the liquid bromine

We will use the following expression.

Q = c × m × ΔT

Q = 0.226 J/g.K × 31.2 g × 2.30 K

Q = 16.2 J

If MgCl2 (aq) has a molarity of 2.5 M, then the molarity of the Cl-1 ions is ____ M.

Answers

Answer:

molarity of Cl⁻ ions = 5.0 M

Explanation:

The molarity of a solution expresses the amount in moles of a solution present in a litre of solvent. Its unit is mol/L or mol/dm³ written as M.

MgCl₂ when dissolved to form an aqueous solution dissociates into positive and negative ions, Mg²⁺and Cl⁻ ions.

Equation of the dissociation of MgCl₂ in aqueous solution is given below:

MgCl₂(aq) -----> Mg²⁺(aq) + 2Cl⁻(aq)

1 mole of aqueous MgCl₂ produces 2 moles of chloride ions, Cl⁻

Molar concentration of MgCl₂(aq) = 2.5 M

Molarity of chloride ions = number of moles of Cl⁻ ions * molarity of MgCl₂

molarity of Cl⁻ ions = 2 * 2.5 M

molarity of Cl⁻ ions = 5.0 M

Identify which of the following equations are balanced.A. 6Li(s)+N2(g)→2Li3N(s)6Li(s)+N2(g)→2Li3N(s).B. 2KMnO4(s)→K2MnO4(s)+MnO2(s)+O2(g). C. 2KClO3(s)→2KCl(s)+O2(g)2KClO3(s)→2KCl(s)+O2(g). D. Mg(s)+N2(g)→Mg3N2(s)Mg(s)+N2(g)→Mg3N2(s).

Answers

Answer:

love u baby doll thanks for the help

what is the composition and structure of ionic compounds​

Answers

Answer:

Sodium and chlorine ions come together to form sodium chloride or NaCl. The sodium atom in this compound loses an electron to become Na+, while the chlorine atom gains an electron to become Cl-. Together, they form a neutral compound because the ions balance each other out.

Explanation:

the molar ratio of cucl2 to Al should be

Answers

Answer:

1) The chemical equation is:

 

Al +  CuCl2 ---> Cu + AlCl3

2) You have to balance the equation to state the coefficients:

2Al + 3CuCl2 ---> 3Cu + 2Al Cl3

3) Now the coefficients tell you the molar ratios.

2 mol Al : 3 mol CuCl2 : 3 mol Cu : 2 mol AlCl3

4) The molar ratio of CuCl2 to Al is:

3 mol Cu Cl2 / 2 mol Al = 3/2 = 1.5

Explanation:

Which body of water will have a greater influence on an area?
A. river
B. lake
C. stream
D. ocean

Answers

Answer:

The correct option is A

Explanation:

Water from a river is used for many activities in a community. These activities could include (but not limited to) tourism, drinking for animals, local transport, irrigation for nearby farming, recreation (as in swimming), habitat for some living organisms among others. Rivers are not limited by what limits the influence of oceans such as taste (it's saltiness, which cannot be used in farming also) and wave current.

Question 10
2 pts
(2 points) What is the molarity of a solution when 25.0 mL of 0.500 M NaCl is diluted to 150.0 mL?
Show your work. No work = no credit.
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# C V ATT TT:
12pt
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Answers

Answer:

M₂  = 0.08 M

Explanation:

Given data:

Initial volume = 25.0 mL

Initial molarity = 0.500 M

Final volume = 150.0 mL

Final molarity = ?

Solution:

Formula:

M₁V₁          =     M₂V₂

0.500 M × 25.0 mL = M₂ ×  150.0 mL

M₂  = 0.500 M × 25.0 mL /   150.0 mL

M₂  = 12.5 M.mL /150.0 mL

M₂  = 0.08 M

Select the molecule where free rotation around one or more bonds is not possible. Group of answer choices N2H4 C2Cl4 NH3 C2H6 CCl4

Answers

Answer:

C₂Cl₄

Explanation:

To know if free rotation around a bond in a compound is possible, we need to see the structure of the compound (picture in attachment).

In single bonds, which are formed by σ bonds, the atoms are not fixed in a single position, and free rotation is permitted.

Double and triple bonds are formed by a σ bond and one or two π bonds, respectively. These bonds do not allow rotation, since it is not possible to twist the ends without breaking the π bond.

The chloroethylene (C₂Cl₄) has two carbons with an sp2-sp2 hybridization, they are bonded together by a double bond. Free rotation on this bond is not possible, because six atoms, including the carbon atoms, doubly bonded and the four chlorine atoms bonded to them, must be on the same plane.

The equilibrium constant, Kc, for the following
reaction is 10.5 at 350 K.
2CH2Cl2(g) double arrow CH4(g) + CCl4(g)
If an equilibrium mixture of the three gases in a 12.7
L container at 350 K contains 0.205 mol of
CH2Cl2(g) and 0.414 mol of CH4, the equilibrium
concentration of CCl4 is......
mol.

Answers

Answer:

2CH2Cl2(g) Doublearrow CH4(g) + CCl4(g)

0.205 moles of CH2Cl2 is introduced. Let by the time an equilibrium is reached x moles each of CH4 and CCl4 are formed => remaining moles of CH2Cl2 are 0.205-x

i.e at equilibrium the concentration on CH2Cl2 is (0.205-2x) mol/L, CH4 is x mol/L, CCl4 is x mol/L

Now the equilibrium constant equation : K = [CH4][CCl4]/[CH2Cl2]^2 ([.] - stands for concentration of the term inside the bracket)

10.5 = x*x/(0.205-2x)^2

=> 10.5(4x^2-0.82x+0.042) = x^2

=>42x^2-8.61x+0.441=x^2

=>41x^2-8.61x+0.441 = 0

This is a Quadratic in x, solving for the roots, we get x = 0.0886 , x = 0.121

The second solution for x will lead 0.205-2x to become negative, so is an infeasible solution.

Therefore equilibrium concentrations of the products and reactants correspond to x=0.0886 and they are , [CH2Cl2] = 0.205-2*0.0886 =0.0278 mol/L , [CH4] = 0.0886 mol/L , [CCl4] = 0.0886 mol/L

What mass of Al(OH)3 is needed to completely react with 17.9g of HCl?

Answers

Answer:

12.8 g

Explanation:

Step 1: Write the balanced neutralization reaction

Al(OH)₃ + 3 HCl ⇒ AlCl₃ + 3 H₂O

Step 2: Calculate the moles corresponding to 17.9 g of HCl

The molar mass of HCl is 36.46 g/mol.

17.9 g × 1 mol/36.46 g = 0.491 mol

Step 3: Calculate the moles of Al(OH)₃ that completely react with 0.491 moles of HCl

The molar ratio of Al(OH)₃ to HCl is 1:3. The reacting moles of Al(OH)₃ are 1/3 × 0.491 mol = 0.164 mol

Step 4: Calculate the mass corresponding to 0.164 moles of Al(OH)₃

The molar mass of Al(OH)₃ is 78.00 g/mol.

0.164 mol × 78.00 g/mol = 12.8 g

Use the periodic table to match each of the following element symbols to its name, atomic mass, or atomic number. (3 points)


1.
Se


2.
S


3.
Sn


a.
Tin
b.
78.971 u (atomic mass)
c.
16 (atomic number)

Answers

Answer:

Tin I thunk

Explanation:

I think

Answer:

sn = tin

se = 78.971 u (atomic mass)

s = 16 (atomic number)

A mass scale reads 10 kilograms on earth, what would it read on the moon?

Answers

It would still read 10 kilograms on the moon. Mass is the same on Earth and the moon. That seems like a trick question! Hope this helps :)

The mass of water in a single popcorn kernel was found to be 0.905 grams after it popped at a temperature of 175 °C. Using the information given in the Introduction, calculate the amount of heat in kilojoules required to pop this single kernel if the room temperature was recorded to be 21.0 °C.

Answers

Answer:

0.583 kilojoules

Explanation:

The amount of heat required to pop a single kernel can be calculated using the formula as follows:

Q = m × c × ∆T

Where;

Q = amount of heat (J)

m = mass of water (g)

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

∆T = change in temperature

From the given information, m = 0.905 g, initial temperature (room temperature) = 21°C , final temperature = 175°C, Q = ?

Q = m × c × ∆T

Q = 0.905 × 4.184 × (175°C - 21°C)

Q = 3.786 × 154

Q = 583.044 Joules

In kilojoules i.e. we divide by 1000, the amount of heat is:

= 583.04/1000

= 0.583 kilojoules

A photovoltaic cell converts light into electrical energy. Suppose a certain photovoltaic cell is only 63.5% efficient, in other words, that 63.5% of the light energy is ultimately recovered. If the energy output of this cell is used to heat water, how many 520 nm photons must be absorbed by the photovoltaic cell in order to heat 10.0 g of water from 20.0°C to 30.0°?

Answers

Answer:: A photovoltaic cell converts light into electrical energy. Suppose a certain photovoltaic cell is only 63.5% efficient, in other words, that 63.5% of the light energy is ultimately recovered. If the energy output of this cell is used to heat water, how many 520 nm photons must be absorbed by the photovoltaic cell in order .

Explanation:

H3C-CH2-C-CH2-CH2-CH3
CH-CH3
what is the formula of butane​

Answers

Answer:

Butane : CH3 - CH2 - CH2 - CH3

Explanation:

The word Butane has "But" as preffix which stands for 4 carbon atoms & "ane" as suffix which tells that the compound is of alkane homologous series .

What is the “nature” of the water cycle?

Answers

Answer:

Continuously recurring, or cycling maybe?

Answer:

a process that recirculates earth's water through the stages of evaporation condensation and collection. The water from lakes, oceans, rivers and other water bodies began to evaporate vapor from the water bodies, condensates and the clouds later causing precipitation

Which compounds are organic?
a. CO2
b. NaCl
c. C6 H12 O6
d. CH2P (C6H5)3

Answers

Answer:

All of them except NaCl

Explanation:

Organic compounds are compound that basically contain carbon-hydogen bonds. Salt (NaCl) doesn't have carbon, and the rest does. So I think that A, C, and D are the answers.

I hope this helps!

Calcium metal reacts with fluorine gas to form solid calcium fluoride. When the reaction is balanced, what coefficient is in front of fluorine gas?

A. 1
B. 2
C. 7
D. 3

Answers

Answer:

B= 2

Explanation:

Chemical equation:

Ca + F      →   CaF₂  

Balance chemical equation:

Ca + 2F      →   CaF₂  

Step 1:

Ca + F      →   CaF₂

Left hand side             right hand side

Ca = 1                             Ca = 1

F = 1                                F = 2

Step 2:

Ca + 2F      →   CaF₂

Left hand side             right hand side

Ca = 1                             Ca = 1

F =  2                              F = 2

A::A represents
1. two lone pairs of electrons.
2. one lone pair of clectrons.
3. a double bond.
4. quadruple bond.​

Answers

Answer:

1

Explanation:

because its to long just why its useless

6. What causes the phases of the moon?

Answers

Answer:

The rotation of the Earth.


A geneticist has discovered a new compound that is made up of a small number of identical
subunits. The subunits are joined end to end in long chains. Based on this information, what
best can be concluded about these subunits?

A. They are ketones.

B. They are hydrocarbons.

C. They are monomers.

D. They are polymers.

Answers

Answer:

They are monomers.

Explanation:

Edg 2020

Answer:

C.

monomers

Explanation:

edg. 2020 read and use common sense

What information would you need to determine the most likely resonance structure for the molecule?
A. The formal charge of each atom
B. The polarity of each covalent bond
C. The Lewis structure of the molecule
D. The bond length of each covalent bond​

Answers

Answer:

The Formal Charge of Each Atom

Explanation:

I just took the test!

Answer:

A. The formal charge of each atom

Explanation:

Which statement describes the conditions in which diamonds form?

Answers

Answer:

The answer to the question, 'which statement describe the formation of diamonds is option C. Diamond deposits are formed in the earth mantle and release to the earth surface by mean of volcanic eruptions which produce kimberlites. The formation of diamonds require very high temperatures and pressures. These conditions exist below the earth surface at the depth of about 150 kilometers and 1050 degree Celsius temperature.

Explanation:

Answer:

Diamond deposits are formed in the earth mantle and release to the earth surface by mean of volcanic eruptions which produce kimberlites

Explanation:


2. In a chemistry experiment, 10 g of urea NH2CONH2 (s) is dissolved in 150 ml of water in a simple calorimeter. A
temperature decrease of 3.7°C is measured. Calculate the molar enthalpy of solution for urea.

Answers

Answer:In a chemistry experiment, 10g of urea, NH2CONH2 (s), is dissolved in 150 mL of water in a simple calorimeter. A temperature decrease of 3.7oC is measured. Calculate the molar enthalpy of solution (∆Hs). ... an ideal gas B if 0.622 g sample of gas B occupies a volume of 300 mL at 35 °C and 1.038 atm.

Explanation:

Choose all the answers that apply.
Which of the following statements are true?
OThe space between neurons is called a synapse.
OThe nucleus of a neuron is located in the cell body.
O Practice can increase the speed of neuron signal transfer.
0Axons carry messages toward the cell body.

o Electrical impulses in neurons go two ways.

Answers

Answer:

I think this the right answer maybe, the space between neurons is called a synapse. The nucleus of a neuron is located in the cell body. Axons carry messages toward the cell body. These are the true ones I think.

Explanation:

Answer:

1,2, and 4

Explanation:

The graph shows the distance an object travel in 11 seconds which answer choice best describes the movement of the object between the times of 0 and 6 seconds on the graph

Answers

Answer:

its moving at a constant speed

Explanation:

i did the test and got it right

Select the pair of compounds that you would expect to form a homogeneous solution based on intermolecular forces. Please choose the correct answer from the following choices, and then select the submit answer button. Answer choices CBr4 and NH3 CCl4 and H2O NH3 and H2O Br2 and HCl

Answers

Answer:

NH3 and H2O

Explanation:

In chemistry, the overarching principle of like dissolve like decides the solubility of one substance in another. This principle is ultimately hinged on the idea of intermolecular forces existing between substances. Polar substances dissolve polar substances while nonpolar substances dissolve nonpolar substances in accordance with this principle.

Both NH3 and H2O are polar substances that contain the hydrogen bond. Intermolecular hydrogen bonding interaction accounts for the solubility of NH3 in H20.

Other Questions
Which number(s) below belong to the solution set of the equation? Check allthat apply.x + 12 = 13D A. 13B. 312O C. 14O D.OO E. 1F. 25 Evaluate: 3x^2 + y when x=1 and y=-3 * You're smart, thanks so much and do you know the missing answers to this: The Endothelial cell lining a ANSWER adjacent to a site of inflammation will express on their cell surface adhesion molecules which will be complementary for a set of ANSWER molecules expressed on the surface of circulating ANSWER. factor the expression below-r -8 4+a cuz I dont get this Use the properties of exponents to simplify: 3^0 1 True False What is the product of 1/2x1/8 A 5.00 kg firecracker explodes into two parts: one part has amass of 3.00 kg and moves at a velocity of 25.0 m/s towardsthe west. The other part has a mass of 2.00 kg. What is thevelocity of the second piece as a result of the explosion?a -28.7 m/sb 15.8 m/sC-37.5 m/sd 43.2 m/s What might be reasons that small-company stocks earn higher returns than large-company stocks on average? if a patient is in R.R. in what part of the hospital is the patient located Which statement about 8 x 9/9 is true? A) The product will be greater than 8. B) The product will be less than 1. C) The product will be equal to 8. D) The product will be less than 8. Thanks for helping.Have a good night or day Which of the following BEST describes the ATP cycle?A. ATP is a low energy molecule that absorbs energy that is given off in a chemical reaction.B. ATP is a high energy molecule that releases energy when a phosphate is released.C. ATP converts to ADP by releasing a molecule of oxygen.D. Once ATP releases energy, it is destroyed and is never used again. Possessive plural nouns (year 6) 1. Define, as simply as you can, reinforcement and punishment.2. Explain how one might accomplish reinforcement and punishment through the use of positive reinforcement, negative reinforcement, positive punishment, and negative punishment. Include examples where appropriate. - 1/2 - 2/3v = 4/5 please help how to read poetry explanation Suppose f(x) = abis an exponential GROWTH function. Which function, then, represents exponential DECAY?A)f(x) = abB)f(x) = ab*.4C)f(x) = a(b-1)D)104) = a(5 Using only the letters in the words Happy Thanksgiving, make as many other words as possible. Help!! A spinner is divided into many sections of equal size. Some sections are red, some are blue, and the remaining are green. The probability of the arrow landing on a section colored red is 9 over 20 . The probability of the arrow landing on a section colored blue is 6 over 20 . What is the probability of the arrow landing on a green-colored section? (1 point)Group of answer choices15 over 2011 over 206 over 205 over 20