Answer:
frequency = 8.22 x 10¹⁴ s⁻¹
Explanation:
An electron's positional potential energy while in a given principle quantum energy level is given by Eₙ = - A/n² and A = constant = 2.18 x 10⁻¹⁸j. So to remove an electron from the valence level of Boron (₅B), energy need be added to promote the electron from n = 2 to n = ∞. That is, ΔE(ionization) = E(n=∞) - E(n=2) = (-A/(∞)²) - (-A/(2)²) = [2.18 x 10⁻¹⁸j/4] joules = 5.45 x 10⁻¹⁹ joules.
The frequency (f) of the wave ionization energy can then be determined from the expression ΔE(izn) = h·f; h = Planck's Constant = 6.63 x 10⁻³⁴j·s. That is:
ΔE(izn) = h·f => f = ΔE(izn)/h = 5.45 x 10⁻¹⁹ j/6.63 x 10⁻³⁴ j·s = 8.22 x 10¹⁴ s⁻¹
If the xylem vessels of a plant are plugged :
a)
No food will be made
b)
The plant will wilt (shrivel)
c)
The leaves will turn yellow
Answer:
b is right answer because xylem provide nutrition and water to the plant
What are the Chemical properties of Ethyne
Answer:
Ethyne is a colourless gas with a characteristic smell. It has a melting point -81oC. It has a boiling point -84oC.
Explanation:
An example of a cell is a ____________ cell.
Answer:
Prokaryotic / Eukaryotic
For the following element, predict the most likely oxidation number (charge) for its corresponding ion.
Phosphorus
A. P+1
B. P+3
C. P-1
D. P-3
The most likely ion of Phosphorous is P³⁻ (group 15) since gaining three electrons is the most energetically favorable way for it to follow the octet rule.
Because the charge on ions is equivalent to their oxidation state, then -3 is the most likely oxidation number of Phosphorous.
Which gases are needed for animal and plant respiration? Select two options. FAST ITS TIMED
oxygen
nitrogen
carbon dioxide
neon
carbon
Can a non-metal replace a metal in a single replacement reaction? If yes, is a non-metal always not able to replace a metal in a single replacement reaction?
Non-metals will never replace metals or vice versa, they'll only replace itself or the only type of reaction that it is or element that it is.
Someone pls help me I will make you brain
Answer:
the answer is A for this question
which elements are designated as the alkali metals
Answer:
Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Cesium (Cs), and Francium (Fr).
Explanation:
Six chemical elements in Group 1, the leftmost column in the periodic table.
Hope this helps!
What is 40g of calcium and 71 g of chlorine
why do garden manure and compost fertilize the soil
gardens arent real the government is lying the world is a simulation
As the soil absorbs manure, nutrients are released. This enriches the soil, which in turn helps the plants. The most important benefit of using manure in the garden is its ability to condition the soil For instance, mixing manure with sandy soils helps to retain moisture levels.
please help???? i dont know this
Answer:
a and b
Explanation:
Answer:
The after-rain smell is produced by an interaction between rain and the oils released by plants. Due to chemical reaction between the rain water and oils secreted out by the plants
A homemade volcano can be created by combining baking soda and vinegar. When it erupts, carbon dioxide gas is released. When vinegar reacts with baking soda carbon-dioxide gas is released.
The Statue of Liberty has turned green over time due to the reaction of copper with ,oxygen,carbon dioxide and water.
Explanation:
Chemical change is defined as those change in which arrangement of atoms present in the substance changes and leads to formation of new substance.
The after-rain smell is produced by an interaction between rain and the oils released by plants. Due to chemical reaction between the rain water and oils secreted out by the plants
A homemade volcano can be created by combining baking soda and vinegar. When it erupts, carbon dioxide gas is released. When vinegar reacts with baking soda carbon-dioxide gas is released.
[tex]CH_{3} COOH+ NaHCO_3[/tex]→[tex]CO_2+H_2O+CH_3COONa[/tex]
The Statue of Liberty has turned green over time due to the reaction of copper with ,oxygen,carbon dioxide and water.
[tex]Cu+O_2+CO_2+H_2O[/tex]→[tex]Cu_2(OH)_2CO_3[/tex]
Physical change is defined as those changes which leads to change in shape, size or state of the substance changes. No new substance is formed.
Explain the formation of planets based on our knowledge of the solar system
Planets form from particles in a disk of gas and dust, colliding and sticking together as they orbit the star. The planets nearest to the star tend to be rockier because the star's wind blows away their gases and because they are made of heavier materials attracted by the star's gravity.
under what circumstances can an atom emit a photon
Answer:
Here
Explanation:
When the atom absorbs energy, it can move to a higher energy state, or excited state. Under what circumstances can an atom emit a photon? A photon is emitted when an atom moves from an excited state to its ground state or to a lower-energy excited state.
Someone pls help me I will make you brain
Answer:
I would go with the first option. It shows how people having been releasing more and more carbon dioxide into the atmosphere.
Explanation:
4. Explain error and how it can impact your results from an experiment
Random errors will shift each measurement from its true value by a random amount and in a random direction. These will affect reliability (since they're random) but may not affect the overall accuracy of a result.
Why do we use the mole concept ??
Answer:
Here
Explanation:
Chemists need the mole concept to bridge the gap between the microscopic world of atoms to the macroscopic world of humans. As you know, the molecular level consists of particles that are invisible to us.
Answer:
it allows us to count atoms and molecules by weighing macroscopic amounts of material.
When a spoonful of salt is dissolved in a pan filled with water, the water is called the...
Select one:
a. solute.
b. solution.
c. solvate.
d. solvent.
Answer:
water is called solvent
Answer:
Option d (solvent)
Explanation:
In salt solution, salt is the solute. A solvent is the substance that does the dissolving – it dissolves the solute. In salt solution, water is the solvent
what kind of reaction is happening when glaze is fired
Answer:
Oxidation and Reduction occurs
Explanation:
is there a pattern in how one can predict how many covalent bonds an atom will form?
Answer:
In molecules, there is a pattern to the number of covalent bonds that different atoms can form. Each block with a number indicates the number of covalent bonds formed by that atom in neutral compound
Explanation:
I don't really know the answer sorry
calculate the mass required to prepare 2.5 L of 1.0 M NaOH solution. Given that the molar mass for NaOH is 40 g/mol.
Answer:
The required mass to prepare 2.5 L of 1.0 M NaOH solution is 100 g
Explanation:
We do this by preparing the equation:
Mass = concentration (mol/L) x volume (L) x Molar mass
Mass = 1.0 M x 2.5 L x 40 g/mol
Mass = 100 g
Answer:
[tex]100\; \rm g[/tex] of [tex]{\rm NaOH}\; (s)[/tex] would be required.
Explanation:
The quantity of solute in a solution of concentration [tex]c[/tex] and volume [tex]V[/tex] would be [tex]n = c \cdot V[/tex].
It is given that volume [tex]V = 2.5\; \rm L[/tex] for the solution in this question. It is also given that the concentration of the [tex]\rm NaOH[/tex] solute in this solution is [tex]c = 1.0\; \rm M[/tex], which is the equivalent to [tex]c = 1.0\; \rm mol \cdot L^{-1}[/tex].
Apply the equation [tex]n = c \cdot V[/tex] to find the quantity of [tex]\rm NaOH[/tex] in this solution:
[tex]\begin{aligned}n &= c \cdot V \\ &= 1.0\; \rm mol \cdot L^{-1} \times 2.5\; \rm L \\ &= 2.5\; \rm mol\end{aligned}[/tex].
Multiply the quantity [tex]n[/tex] of [tex]\rm NaOH[/tex] in this solution with the formula mass [tex]M[/tex] of [tex]{\rm NaOH}\![/tex] to find the corresponding mass:
[tex]\begin{aligned}m &= n \cdot M \\ &= 2.5\; \rm mol \times 40\; \rm g \cdot mol^{-1} \\ &= 100\; \rm g\end{aligned}[/tex].
Thus, this solution would contain [tex]100\; \rm g[/tex] of [tex]{\rm NaOH}[/tex].
It would thus take [tex]100\; \rm g[/tex] of [tex]{\rm NaOH}[/tex] to prepare this solution.
Which choice is an element?
A. Salad
B. Sugar
C. Water
D. Potassium
Answer: D. Potassium
Explanation:
A. Salad- a mixture of vegetables or fruits❌
B. Sugar- a compound made up of many elemnts❌
C. Water- a molecule made up of two elements (water and hydrogen)❌
D. Potassium- the only pure element of the options provided.✅
Answer:
D, potassium
Explanation: took test ! btw
What are the three zones in almost all human cells?
O cytoplasm, mitochondria, plasma membrane
O ribosomes, genetic material, cytoplasm
O nucleus, cytoplasm, plasma membrane
O mitochondria, genetic material, plasma membrane
PLEASE HELP!!!!!!! (in a few minutes please)
B
Hope this helped you, have a good day bro cya)
Answer: Although metamorphic rocks typically form deep in the planet's crust, they are often exposed on the surface of the Earth.
Explanation:
How many cc of methane at not is required to react completely with 20cc of oxygen? Please helps meee!
Answer:22.4 L methane reacts with 44.8 L of oxygen to give 22.4 L of CO
2 and 44.8 L of water.
Explanation:
is it true or false when the there are too many protons making the nuclei unstable, it will undergo a positron decay and a proton will turn into a neutron.
Answer:
True
Explanation:
As the number of protons in the nucleus increases, the number of neutrons needed for a stable nucleus increases even more rapidly.
Only_________are involved in forming chemical bonds betwen two atoms
a. s orbital electrons
b. p orbital electrons
c. valence electrons
d. innermost electrons
C)
Only valence electrons are involved in forming chemical bonds betwen two atoms.
Hope this helped you- have a good day bro cya)
Someone pls help me I will make you brain
Answer:
I believe the answer is II and III
Explanation:
I'm not sure if III is right cause I cannot read the last word but I think it's OK.
Hope this helped :)
Summarize Hooke's observations of cork under the microscope
Answer:
I don't know
Explanation:
pls I need a little bit answer
2. Water should not be used to put electrical fires?
Answer:
You should never throw water on an electrical fire because water conducts electricity and you could be electrocuted.
Please mark 4 brainliests
what is the wavelength of an X-ray having a frequency of 4.80 x 1017 Hz
Answer:
Refer to the attachment