Sounds that a person hears that never go away can interfere with studying
and sleeping.

A.True
B.False

Answer:

Convert grams of Mg to moles

Explanation:

In stoichiometric calculations, the first thing is always to balance the chemical reaction equation. However, in this particular instance, the equation is already balanced; 2Mg + O2 ---------->2MgO as shown in the question.

Hence, what Niven now has to do is to convert grams of Mg to moles so that the amount of MgO obtained can be calculated and subsequently converted to mass.

Answer:

d = 20.89 g/cm³

Explanation:

Given data:

Length of block = 4.20 cm

width of block = 3.80 cm

Height of block = 5.40 cm

Mass of block = 1800 g

Density of block = ?

Solution:

First of all we will calculate the volume.

V = l×w×h

V = 4.20 cm ×3.80 cm× 5.40 cm

v = 86.18 cm³

Density:

d =m/v

d =1800 g/ 86.18 cm³

d = 20.89 g/cm³

Answer:

scientists

Explanation:

Answer:

yes

Explanation:

as the salt is a polar compound which means that its dissolvable in water

so the salt would be solute and the water is the solvent

Answer:

A is the correct option

Explanation:

batteries have chemical energy and will convert to electricity and when reached to bulb, it emits light as electromagnetic rays

A gas produced in a chemical reaction can be collected by water displacement. Because the gas is collected over water, it is not pure but is mixed with vapor from the evaporation of the water. Dalton's law can be used to calculate the amount of the desired gas by subtracting the contribution of the water vapor.

Explanation:

oxygen gas is collected bye the downwards displacement of water. because it is only slightly solube in water and is less dence than water. this is my answer

Answer:

B

Explanation:

There was time for the gas to escape from the rock bubbling at the surface

The hole in igneous rocks indicate that the magma cooled too quickly for gas to escape.

Igneous rocks are one of the three main rock types the other two including sedimentary and metamorphic rocks.These rocks are formed by cooling and solidification of lava or magma.

The magma is derived from partial melts in the planet's mantle or crust.Melting is caused by increase in temperature or decrease in pressure or even change in composition.Solidification occurs either below surface which is called as intrusive rocks or on the surface as extrusive rocks.

They are classified according to their texture,mode of occurrence,chemical composition,geometry and mineralogy of rock.The two important variables for classification are mineral composition and cooling history.

Learn more about igneous rocks,here:

https://brainly.com/question/23555197

#SPJ6

Answer:

4.13 moles of Fe.

Explanation:

Given data:

Moles of iron produced = ?

Moles of Fe₂O₃ = 3.5 mol

Moles of CO = 6.2 mol

Solution:

Chemical equation:

Fe₂O₃ +  3CO      →    2Fe + 3CO₂

Now we will compare the moles of iron with CO and Fe₂O₃.

                 Fe₂O₃        :         Fe

                      1             :          2

                  3.5             :         2/1×3.5 = 7 mol

                 CO              :          Fe

                   3               :            2

                 6.2              :        2/3×6.2 = 4.13 mol

The number of moles of iron produced by CO are less it will limiting reactant.

Thus, moles of iron formed in given reaction are 4.13 moles.

Mass of chlorine reacted : 7.1 g

The reaction equation is the chemical formula of reagents and product substances

A reaction coefficient is a number in the chemical formula of a substance involved in the reaction equation. The reaction coefficient is useful for equalizing reagents and products.

Reaction

2Na(s) + Cl₂(g) → 2NaCl(s).

mol Na :

[tex]\tt \dfrac{4.6}{23}=0.2[/tex]

mol NaCl :

[tex]\tt \dfrac{11.7}{58,44 }=0.2[/tex]

limiting reactant = Na(mol NaCl from mol Na, mol ratio : 2 : 2)

mol Cl₂:mol Na=2:1

mol Cl₂ =

[tex]\dfrac{1}{2}\times 0.2=0.1[/tex]

mass Cl₂ :

MW Cl₂ = 71 g/mol

[tex]\tt 0.1\times 71=7.1~g[/tex]

Answer:

21.4

Explanation:

Mass = M/V

42.8/2.0 = 21.4

:)

Answer:You'd wind up with a pH-neutral substance.

Answer:

C

Explanation:

collisions of galaxies

The low energy radiations found in space have been evident of collisions of galaxies. Thus, option C is correct.

Astronomers have been dealing with the stars, galaxies, and other space. Outer space has consisted of the various galaxies that have been continuously formed with collisions and movement.

The low energy radiations found in space have been because of the energy that has been liberated due to the collisions of the galaxies. Thus, option C is correct.

For more information about the astronomers, refer to the link:

https://brainly.com/question/4587708

An echo or a reverberation can result from the reflection of sound waves off physical surfaces. Small rooms with dimensions of 17 meters or fewer, breadth, and length frequently experience reverberation.

When two different media come together at an interface, a wavefront might change direction so that it returns to the first medium, which is known as reflection. The reflection of light, sound, and water waves are typical examples.

According to the law of reflection, the angle of incidence and angle of reflection are equal. The reflected wave will typically be inverted for mechanical waves traveling from a less dense medium into a more dense medium.

A portion of a wave will often bounce back into the original medium when it encounters the interface between two different media. We call this process "reflection." Optical reflection in mirrors, where light waves reflect off a smooth surface, is a well-known example of reflection.

Thus, An echo or a reverberation can result from the reflection of sound waves off physical surfaces.

To learn more about reflection, follow the link;

https://brainly.com/question/15487308

#SPJ2

Answer/Explanation:

A) The independent(test) variable controls the dependent variable. A good way to think about this is that the independent variable has nothing that effects itself. The dependent variable is 'dependent' or reliant on the independent variable.

Answer:

A

Explanation:

Answer:

The products will also have one S and four O atoms.

Explanation:

According to Law of Conservation of Matter, " Matter can neither be created nor destroyed, but it can be changed from one form into another".

Answer:

6 Cl atoms

Explanation:

In one molecule of ZnCl2, we have 2 atoms of Cl

Therefore, in 3 molecules of ZnCl2, we'll have 3(2) atoms of Cl = 6 atoms of Cl.

please mark brainliest

The 15 kg block require more work to raise by 4 meter compare to  20 kg blocks .

The free body diagram is attached below,

We know that,  Weight [tex]W=m*g[/tex]

where m is mass of object and g is gravitational acceleration.

Value of  [tex]g=9.8m/s^{2}[/tex]

So that, weight is depend on mass of object.

And , [tex]workdone=force*distance[/tex]

Work done require to raise 15kg block by 4 m is,

                 [tex]W=15*4*g=60g[/tex]

Work done require to raise 20kg block by 2 m is,

               [tex]W=20*2*g=40g[/tex]

Hence, The 15 kg block require more work to raise by 4 meter compare to  20 kg blocks .

Learn more:

https://brainly.com/question/21854305

Answer:

the solvent and solution

Explanation:

Solutions having solute in gaseous state and solvent in liquid state, are called Gas - Liquid Solutions. For example - Solution (mixture) of oxygen in water, mixture of carbon dioxide in water. Coca cola, a beverage, is an example of gas - liquid solution, as it has carbon dioxide dissolved in water.

In a gas-liquid solution, the substances that naturally takes a liquid state is: (E) the solvent and the solution.

Dissolution can be defined as the process of dissolving or dissociating a solute in solid, liquid or gaseous phase into fragmented particles by a solvent in order to form a solution.

Gas-liquid solution that have solute in their gaseous state and solvent in their liquid state.

For liquid and gases, the substance to be dissolved must form a non-covalent bond with the solvent, in order to produce a solution.

In Science, a solute refers to a substance that is typically dissolved in a liquid solvent such as water, coffee, tea, etc., to produce a solution.

Additionally, a solute maybe completely ionized, partially ionized, or it may remain intact during the process of dissolution.

Read more: https://brainly.com/question/24057916

Answer:

I think it's B

Explanation:

A and C are out of the equation because Earth's axis isn't tilted on them and has the entirety of Argentina covered in shadow. The only answer left would be B.

Answer:

Explanation:

h= e/v

6.022 x 10^23 = 4.36 x 10^-18/ v

v= 6.58 x 10^15

C= lambda x frequency

3.00 x 10^8= 6.58 x 10^15 x lambda

lambda (y)= 4.56 x 10^-8

Answer:

Explanation:

λ = hc/E

6.626 x 10^-34 J-s x 2.998 x 10^8 m-s^-1

                     4.36 x 10^-18 J

= 4556.13486239

= 4.56 x 10^1 nm

Answer:

Explanation:

From the work of Krogh in 1918 until the present time, a very wide range of values for oxygen diffusion coefficients has been reported1–5 ranging from 1.1 × 10−4 to 4 × 10−8 cm2 sec−1.

Answer:

Gas(this is because we are only considering that there are 3 states of matter, while in reality there are 5.)

Explanation:

There are actually 4 states of matter excluding a 5th one that has just been discovered, but if we consider that there are only 3 states of matter then the particles move the fastest in gases. As the particles are the furthest apart.

1.calcium monohydroxid

2.sulfur dioxide

3.sry don't know

Answer:

Please find the answers to the frequency and energy to each question below

Explanation:

Using the formulas;

λ = v/f

E = hf

Where;

λ = wavelength (metres)

v = speed of light (2.998 × 10^8 m/s)

f = frequency (Hz)

E = Energy of photon (J)

h = Plancks constant (6.63 × 10^-34 J.s)

1.) λ = 568cm = 5.68m

f = v/λ

f = 2.998 × 10^8 ÷ 5.68

f = 0.5278 × 10^8

f = 5.278 × 10^7 Hz

E = hf

E = 6.63 × 10^-34 × 5.278 × 10^7

E = 34.99 × 10^(-34+7)

E = 3.499 × 10^-26 J

2). λ = 726cm = 7.26m

f = v/λ

f = 2.998 × 10^8 ÷ 7.26

f = 0.413 × 10^8

f = 4.13 × 10^7 Hz

E = hf

E = 6.63 × 10^-34 × 4.13 × 10^7

E = 27.38 × 10^(-34+7)

E = 2.74 × 10^-26 J

3). λ = 482cm = 4.82m

f = v/λ

f = 2.998 × 10^8 ÷ 4.82

f = 0.622 × 10^8

f = 6.22 × 10^7 Hz

E = hf

E = 6.63 × 10^-34 × 6.22 × 10^7

E = 41.24 × 10^(-34+7)

E = 4.124 × 10^-26 J

4). λ = 879cm = 8.79m

f = v/λ

f = 2.998 × 10^8 ÷ 8.79

f = 0.341 × 10^8

f = 3.41 × 10^7 Hz

E = hf

E = 6.63 × 10^-34 × 3.41 × 10^7

E = 22.61 × 10^(-34+7)

E = 2.26 × 10^-26 J

5). λ = 167cm = 1.67m

f = v/λ

f = 2.998 × 10^8 ÷ 1.67

f = 1.795 × 10^8

f = 1.795 × 10^8 Hz

E = hf

E = 6.63 × 10^-34 × 1.795 × 10^8

E = 11.9 × 10^(-34+8)

E = 1.19 × 10^-25 J

6). λ = 572cm = 5.72m

f = v/λ

f = 2.998 × 10^8 ÷ 5.72

f = 0.524 × 10^8

f = 5.24 × 10^7 Hz

E = hf

E = 6.63 × 10^-34 × 5.24 × 10^7

E = 34.74 × 10^(-34+7)

E = 3.474 × 10^-26 J

Answer:

c = 0.39 J/g.°C

Explanation:

Given data:

Energy required = 242.2 J

Mass of copper = 81.6 g

Initial temperature = 27.5°C

Final temperature = 35.2°C

Specific heat capacity of copper = ?

Solution:

Specific heat capacity:

It is the amount of heat required to raise the temperature of one gram of substance by one degree.

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 = 35.2°C -  27.5°C

ΔT = 7.7°C

242.2 J = 81.6 g ×c ×  7.7°C

242.2 J / 81.6 g = c ×  7.7°C

c = 3 J/7.7g.°C

c = 0.39 J/g.°C

Answer:

Because it lose detectable mass.

Explanation:

Law of conservation of mass states that substances involved in chemical reaction do not lose or gain any mass. So the above reactions don't demonstrate the law of conservation of mass because it lose mass

Answer:

This means that waves need a medium to propagate, but light waves propagate where no particles are present. ...