The frequency(f) of this photon : 1 x 10¹⁵ Hz
Further explanationRadiation energy is absorbed by photons
The energy in one photon can be formulated as
[tex]\large{\boxed{\bold{E\:=\:h\:.\:f}}}[/tex]
Where
h = Planck's constant (6,626.10⁻³⁴ Js)
f = Frequency of electromagnetic waves
f = c / λ
c = speed of light
= 3.10⁸
λ = wavelength
A photon has a wavelength of 299 nm.
λ = 299 nm = 299 x 10⁻⁹ m = 2.99 x 10⁻⁷ m
The frequency :
[tex]\tt f=\dfrac{3.10^8}{2.99\times 10^{-7}}\\\\f=\boxed{\bold{1\times 10^{15}~Hz}}[/tex]
Which of the following is not a clue that a chemical reaction has taken place? *
4 points
A solid is formed when two clear solutions are mixed.
A clear solution is added to a red solution, and the result is a blue solution.
A solid is added to water and bubbles form.
A pure solid is heated and turns into a pure liquid.
Answer:
A pure solid is heated and turns into a pure liquid.
Explanation:
No colour change recorded, only change of state, hence this is a physical change - physical changes I.e. change of state and temperature are not chemical reactions.
19. Luke wants to create an aqueous solution that conducts electricity. Which of the following compounds should
he use?
a) KNO3
b) C12H22O11
c) C2H5OH
d) NH4OH
Answer:
I think b) C12H22O11.
Hope this answer is helpful for u.
Which is an example of an object increasing its kinetic energy
Question 3 options:
an airplane after landing on a level runway.
a rocket before launch.
a train stopped at the station.
a mouse running faster after spotting a cat.
Answer:
The answer to this question is the A choice. A rocket before launch.
Explanation:
In the definition of kinetic energy, it says: In physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes.
a compared of magnesium nitric contains 72% of magnesium and 28% of nitrogen. what is the empirical formula of magnesium nitric.
and the answer is Mg 3 N 2
how to do the solution.
The empirical formula is the smallest comparison of atoms of compound =mole ratio of the components
The principle of determining empirical formula
• Determine the mass ratio of the constituent elements of the compound.
• Determine the mole ratio by dividing the percentage by the atomic mass
The empirical formula :
mol ratio Mg : N ⇒
[tex]\tt =\dfrac{72}{24~g/mol}\div \dfrac{28}{14~g/mol}\\\\=3\div 2\rightarrow Mg_3N_2[/tex]
1. Which of the following is a typical characteristic of ionic solids?
A. low melting point
C. no conductivity in solution
B. soft and malleable
D. neutral net charge
How many moles of Mg are present in 62.23 grams of Mg? (Show your calculations for full credit.)
I need to know if is true or false please
Answer:
True
Explanation:
I need to someone to explain the whole being of Chemistry. I do not understand a single thing, nothing makes sense to me. Literally, I'm going to fail this class because I do NOT understand a single thing taught to me. Maybe it's because I was mistakenly put into Chemistry Pre AP instead of on level but it's so hard and- I just do not get it.
Answer:
Explanation:
In Pre-AP Chemistry, the development of models to explain their macroscopic observations is a primary means through which students develop an understanding of the molecular world.
You will be forced to think and apply concepts to new situations, and even derive your own theories from application. This is excellent preparation for the higher levels of thinking required in college.
Chemistry, the science that deals with the properties, composition, and structure of substances (defined as elements and compounds), the transformations they undergo, and the energy that is released or absorbed during these processes.
In if the reaction below 49 grams of Fe3O4 produces a 78.25% yield of Fe. How many grams are produced? Fe3O4 + 4H2 = 3Fe + 4H2O
Imagine the = is an arrow
Fe produced : 27.53 g
Further explanationReaction
Fe₃O₄ + 4H₂ = 3Fe + 4H₂O
mol Fe₃O₄ (MW=233.55 g/mol) :
[tex]\tt \dfrac{49}{233.55 g/mol}=0.21[/tex]
mol ratio Fe₃O₄ : Fe = 1 : 3, so mol Fe :
[tex]\tt 3\times 0.21=0.63~g/mol[/tex]
mass Fe(Ar=55,845 g/mol)
[tex]\tt 0.63\times 55,845=35.18~g[/tex]
grams produced :
[tex]\tt \%yield=\dfrac{actual}{theoretical}\times 100\%\\\\actual=\%yield\times theoretical\\\\actual=78.25\%\times 35.18\\\\actual=27.53~g[/tex]
Good day please help me thank you
Answer:
D Transportation it makes sence if it doesn't just re read it
6)
Use VSEPR to predict the electron-pair geometry of O2.
A)
linear
B)
trigonal planar
C)
tetrahedral
ientific
Calc
D)
trigonal bipyramidal
Answer:
A.) Linear
Explanation:
The geometry of the molecular oxygen (O₂) is linear. Thus, option (A) is correct.
What is VSEPR theory?Valence shell electron-pair repulsion theory (VSEPR theory) is used to predict the molecular structure, and bond angles around a central atom of a molecule by using the number of bonds and lone electron pairs in Lewis structure.
The VSEPR model considers that electron pairs present in the valence shell of a central atom have an arrangement so that repulsions between these electron pairs will be minimized by maximizing the distance between them.
The valence electrons of a central atom form either bonding pairs or lone pairs. The electrostatic repulsion of these electrons is minimized when several regions of high electron density maximum possible distance.
The oxygen molecule has linear geometry with a bond angle of 180°. Each oxygen in oxygen molecule has two lone pairs of electrons on it.
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Can a substance be a Lewis acid without being a Bronsted-Lowry acid?
Please argue on it
Answer:
Yes. Since for a substance to be a Bronsted-Lowry acid they have to be able to donate protons, and to be a Lewis acid a substance would have to accept electrons, there are substances which cannot donate protons but can accept electrons.
Explanation:
Hope this helped!
Which choice confirms that one air mass is being replaced by another air mass in a given area?
A. increase in wind
B. high air pressure
C. high air temperature
D. it is impossible to tell.
Answer:
Answer is A
Explanation:
Increase in wind
How are Earth's continents related?
Please help due at 11:45!
What is the percent of SO2 in H2SO4?
Help Please
The percent of SO₂ in H₂SO₄ : 65.3%
Further explanationProust states the Comparative Law that compounds are formed from elements with the same Mass Comparison so that compounds have a fixed composition of elements
%Mass A in AxBy =
[tex]\tt \dfrac{x.Ar~A}{MW~A_xB_y}\times 100\%[/tex]
For SO₂ in H₂SO₄ :
MW SO₂ = 32 + 2.16=64 g/mol
MW H₂SO₄ =2.1+32+4.16=98 g/mol
The percent of SO₂ :
[tex]\tt \dfrac{64}{98}\times 100\%=65.3\%[/tex]
What is the mass of oxygen in 25.0 grams of potassium permanganate , KMnO4?
Answer:
10.76 grams
Explanation:
Given that the amount of [tex]KMnO_4[/tex] is 25.0 grams.
Mass of 1 mole of [tex]KMnO_4[/tex] = 158 grams
The number of atoms in 1 mole of [tex]KMnO_4[/tex] is 4.
Mass of oxygen in 1 mole of [tex]KMnO_4[/tex] = 16\times 4 = 68 grams.
Here, 158 grams of [tex]KMnO_4[/tex] has 68 grams of oxygen
So, the amount of oxygen in 1 gram of [tex]KMnO_4[/tex] = 68/158 grams
Therefore, the amount of oxygen in 1 gram of [tex]KMnO_4[/tex] = [tex]\frac {68}{158}\times 25[/tex] grams
=10.76 grams
Hence, 25 grams of [tex]KMnO_4[/tex] has 10.76 grams of oxygen.
The mass of oxygen in 25.0 grams of potassium permanganate , KMnO4 is 10.13 grams.
molar mass of KMnO₄ = 39 + 55 + 16(4)
molar mass of KMnO₄ = 39 + 55 + 64
molar mass of KMnO₄ = 158 grams
molar mass of oxygen in the compound = 64 g
Therefore,
158g of potassium permanganate has 64 g of oxygen
25 g of potassium permanganate will contain ? of oxygen
cross multiply
mass of oxygen = 25 × 64 / 158
mass of oxygen = 1600 / 158
mass of oxygen = 10.1265822785
mass of oxygen ≈ 10.13 grams
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I literally forgot!
What is chemistry?
Answer:
Chemistry, the science that deals with the properties, composition, and structure of substances (defined as elements and compounds), the transformations they undergo, and the energy that is released or absorbed during these processes
Answer:
hope it helps you a little
Which Ion has the same electron configuration as an Ar atom
1. Cl -
2. F -
3. Li+
4. Na +
Compared to ionic compounds, molecular compounds generally have
A. good conductivity.
B. greater densities.
C. more chemical bonds.
D. a low boiling point.
Compared to ionic compounds, molecular compounds generally have a low boiling point and the correct option is option D.
What are Molecular compounds?
Molecular compounds are held together by covalent bonds. They are also called covalent compounds.
Covalent bonds are responsible for many of the properties of covalent compounds. Covalent compounds have relatively low boiling points, cannot conduct electricity, and may not dissolve in water.
Unlike ionic compounds, covalent compounds do not have freely moving electrons, so they cannot conduct electricity.
The individual molecules of covalent compounds are more easily separated than the ions in a crystal, so most covalent compounds have relatively low boiling points.
Therefore, compared to ionic compounds, molecular compounds generally have a low boiling point and the correct option is option D.
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This reaction type occurs when different atoms in two different compounds trade places.
A) synthesis
B) decomposition
C) double replacement
D) single replacement
Double replacement is the reaction that typically occurs when different atoms in two different compounds trade places (Option C).
What is double-replacement?Double-replacement is a class of chemical reaction where two atoms can exchange their places to generate new combinations.
This type of chemical reaction (double-replacement reaction) is very common in nature.In conclusion, double replacement is the reaction that typically occurs when different atoms in two different compounds trade places (Option C).
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How might water high specific heat capacity affect energy distribution and temperature on earth
Answer:
Water can hold a lot of heat inside it and as the climate starts getting cold, the water releases the heat which heats up the climate
Due to the fact that water has a high heat capacity, its temperature has a very limited range, which causes the coastal areas close to having a similar small daily and seasonal temperature range.
What is specific heat capacity?"When the temperature of a material rises 1 K (or 1 °C), the amount of heat (J) absorbed per unit mass (kg)".
When the weather begins to grow chilly, water releases the heat it has stored inside, warming the environment.
High specific heat of the water makes it temperature resistant, and it helps the earth to maintain its temperature and helps organisms to maintain their functions at a constant temperature of the earth.
Thus, the normal temperature is necessary for maintaining the temperature of the earth and the water bodies maintain the temperature of the earth.
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Answer fast please What system is the stomach part of
A. Circulatory
B. Respiratory
C. Skeletal
D. Digestive
Answer:
the answer is D
Explanation:
i just took the test
Someone please help will mark as brainliest
Answer:
4. A subscript is a sentence below a line. You cannot change subscripts in a chemical formula to balance a chemical equation
5. where's/whats the equation??
6. ^^^
Explanation:
I NEED HELPPPPPP ASAP
Answer:
1. Reactants collect in chloroplasts
2. A chemical reaction occurs
3. Products result as food and water
Sub teacher didn't explain at all :(
Answer:
tell your teacher when he/she get back report him/she
⚠️HURRY PLEASE⚠️FAST IM TIMED⚠️
Which label belongs in the region marked X? Jen makes a Venn diagram to compare active transport and passive transport
a..Moves molecules
b.. Uses energy
c..Moves from low concentration to high concentration
d ..Moves from high concentration to low concentration
Answer:
A
Explanation:
exam review :)
How many moles of water are produced when 5 moles of hydrogen gas react with 2 moles of oxygen gas?
Balanced equation: 2H2 + O2 → 2H2O (5 points)
a. 2 moles of water
b. 4 moles of water
c. 5 moles of water
d. 7 moles of water
Answer:
It is b
Explanation: I did it on the test and got it right
The moles of water are produced when 5 moles of hydrogen gas react with 2 moles of oxygen gas - b. 4 moles of water
The stoichiometric coefficients can be considered in a balanced equation as moles of reactants needed or moles of products formed in the reaction.
In the given case, the balanced chemical equation for this synthesis reaction looks like this2H2 + O2 → 2H2O
from the balanced equation, it is clear that the 2 moles of hydrogen gas and 1 mole of oxygen gas are required to produce 2 moles of water. so it means that the reaction produces twice as many moles of water as you have moles of oxygen gas that take part in the reaction and the same moles as hydrogen atoms present.Here it is given that there are only 2 moles of oxygen which means it is in deficiency however, it will produce 4 moles of water with four moles of hydrogen.Thus, the moles of water are produced when 5 moles of hydrogen gas react with 2 moles of oxygen gas - b. 4 moles of water
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Part B
Do you think that the phases of the moon follow a pattern
Which part of the planet receives the most solar radiation?
A. oceans
B. Polar regions
C. Equator
Pls help me!!
Answer:
C
Explanation:
the sun's rays strike the earth's surface mostly directly at the equator
Compared to ionic compounds, molecular compounds generally have
A. stronger chemical bonds.
B. poor conductivity.
C. a high melting point.
D. lower densities.