The phrase that most accurately describes a chemical change is; "A change on the molecular level."
The major difference between a physical change and a chemical change is that a chemical change involves a change in the composition of a substance.
This implies that the atoms in a substance are rearranged during a chemical change.
This rearrangement of atoms corresponds to change on a molecular level.
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What is the name of the following compound?
CAH₂0?
What is the name of the following compound SO2?
What is the name of the following compound P2F3?
1.calcium monohydroxid
2.sulfur dioxide
3.sry don't know
Astronomers have found low-energy background radiation in every part of the sky that they have studied. This radiation is taken as evidence of energy remaining from which event?
a) supernovas
b) the big bang
C) collisions of galaxies
D)modern decay of unstable atoms
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.
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Can someone help me please ? Click the picture
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
What is the density of a substance that has a mass of 42.8 g and a volume of 2.0 cm^3?
Answer:
21.4
Explanation:
Mass = M/V
42.8/2.0 = 21.4
:)
True or False:
C + 02 - CO2
In the chemical reaction above, the coefficient of oxygen is 2.
False
True
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.
what is the definition of sulphur
Answer:
the chemical element of atomic number 16, a yellow combustible nonmetal.
Explanation:
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Explanation:
A pale-yellow, brittle nonmetallic element that occurs widely in nature, especially in volcanic deposits, minerals, natural gas, and petroleum. It is used to make gunpowder and fertilizer, to vulcanize rubber, and to produce sulfuric acid.
true or false
Protists are eukaryotes that can be classified as animals, plants, or fungi.
and
Pseudopods produce oxygen and are a source of food for other organisms
If I dilute 250 mL of 0.10 M lithium acetate solution to a volume of 750 mL,
what will the concentration of this solution be?
Answer:
0.033 M
Explanation:
From the question given above, the following data were obtained:
Volume of stock solution (V1) = 250 mL
Molarity of stock solution (M1 ) = 0.10 M
Volume of diluted solution (V2) = 750 mL
Molarity of diluted solution (M2) =.?
Thus, we can obtain the molarity of the diluted solution by using the dilution formula as illustrated below:
M1V1 = M2V2
0.1 × 250 = M2 × 750
25 = M2 × 750
Divide both side by 750
M2 = 25/750
M2 = 0.033 M
Therefore, the molarity of the diluted solution is 0.033 M.
how many miles of iron can be produced from 3.5 moles of Fe2O3 and 6.2 moles of CO
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.
1. Calculate the frequency and the energy of light that has a wavelength of 568 cm
2. Calculate the frequency and the energy of light that has a wavelength of 726 cm
3. Calculate the frequency and the energy of light that has a wavelength of 482 cm
4. Calculate the frequency and the energy of light that has a wavelength of 879 cm
5. Calculate the frequency and the energy of light that has a wavelength of 167 cm
6. Calculate the frequency and the energy of light that has a wavelength of 572 cm
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
Sounds that a person hears that never go away can interfere with studying
and sleeping.
A.True
B.False
2
4.6 g of sodium reacts with chlorine to produce 11.7 g of sodium chloride.
What mass of chlorine reacted?
Mass of chlorine reacted : 7.1 g
Further explanationThe 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]
1. When a mechanical wave, such as sound, reflects off a surface, what can the
reflected wave tell you about the surface?
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.
What is reflection ?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.
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(Help ASAP) in the summer many people in Argentina which is located in the southern hemisphere enjoy going to the beach which diagram to the right shows the position of earth when it is summer in Argentina?
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.
The chemical equation below shows the burning of magnesium (Mg) with oxygen (O2) to form magnesium oxide (MgO). 2Mg + O2 Right arrow. 2MgO Niven wants to calculate the mass of MgO that is produced by the burning of 28.0 g of Mg. What is the first step in Niven’s calculation?
- Balance the chemical equation.
- Convert grams of Mg to moles.
- Determine whether heat is given off by this reaction.
- Find the number of Mg atoms in the sample.
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.
How do the test variables (independent variables) and outcome variables (dependent variables) in an experiment compare?
A.
The test variable (independent variable) controls the outcome variable (dependent variable).
B.
The outcome variable (dependent variable) controls the test variable (independent variable).
C.
The test variable (independent variable) and outcome variable (dependent variable) have no affect on each other.
D.
The test variables (independent variables) and outcome variables (dependent variables) are the same things.
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:
How many chlorine atoms in 3ZnCl2
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.
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Is salt and water a solution? Give a reason for your answer.
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
why are gases generally collected by downward displacement of water?
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
In a gas-liquid solution, which of these naturally takes a liquid state?
(A) the solute and the solution
(B) only the solute
(C) only the solvent
(D) the solute and the solvent
(E) the solvent and the solution
(F) only the solution
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.
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Who uses Ionic compounds?
Answer:
scientists
Explanation:
Can you provide an example for both fission and fusion
HELP!!! I need "2 KClO3 (s) → 2 KCl (s) + 3 O2 (g)" in word form
In the reaction of Zn with HCl, 140.15 g of ZnCl2 was actually formed, although the theoretical yield
was 143 g. What was the percent yield?
Zn + 2HCl ➡ ZnCl2 + H2
Answer:
Percent yield = 98%
Explanation:
Given data:
Actual yield of ZnCl₂ = 140.15 g
Theoretical yield of ZnCl₂ = 143 g
Percent yield = ?
Solution:
Formula:
Percent yield = (actual yield / theoretical yield )× 100
Percent yield = (140.15 g/ 143 g)× 100
Percent yield = 0.98 × 100
Percent yield = 98%
How do you find the proton if you are given the mass and charge
A block of iridium has a length of 4.20 cm, a width of 3.80 cm and a height
of 5.40 cm. The mass of the block is 1800 g. Calculate the density.
the following formulas with its creator.
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
Given that 242.2J of energy is required to heat 81.6g of copper from 27.5°C to 35.2°C, find the specific heat of copper.
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
if the reactants of a reaction have one s and four of atoms what will the products have
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".
Does it require more work to raise a 15 kg block by 4 m
or to raise a 20 kg block by 2 m, if both are moving at
a constant velocity? Draw a free-body diagram to help
solve the problem.
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 .
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What do holes in igneous rocks indicate about the cooling process of the magma?
A.The magma cooled too quickly for gas to escape.
B. The molten rock cooled slowly.
C. The magma cooled in layers.
D. The rock cooled with fossils in each of the holes or spaces.
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.
What are igneous rocks?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.
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