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
answer pls ASAP will mark the brainliest
For me that is the first :
Both the identity and the properties of a substance change.
negative ions form when atoms _______ valence electrons.
Answer:
Negatively charged ions are called anions, and an anion is formed when an atom gains an electron. Thus, the atom has an extra charge of electrons,
Explanation:
so it becomes negatively charged.
Negative ions (or anions) are atoms that have gained electrons.
Electrons have a negative charge so if an atom is getting more of them, it's becoming more negative.
Nguyên tử nguyên tố sắt có 26e
a. Viết cấu hình e của sắt
b. Sắt thuộc nguyên tố s,p,d,f
Answer:
1s2 2s2 2p6 3s2 3p6 3d6 4s2
Explanation:
Which statement about exothermic reactions is TRUE?
A.In an exothermic reaction, energy is absorbed, bonds are broken, and the temperature decreases.
B. In an exothermic reaction, energy is released, bonds are formed, and the temperature increases.
Which statement about exothermic reactions is TRUE?
A.In an exothermic reaction, energy is absorbed, bonds are broken, and the temperature decreases.
B. In an exothermic reaction, energy is released, bonds are formed, and the temperature increases.What is the nutrient indicator of Amino Acids?
Answer:
An essential amino acid, or indispensable amino acid, is an amino acid that cannot be synthesized from scratch by the organism fast enough to supply its demand, and must therefore come from the diet.
Explanation:
Hope it helps you
Select the part that contains the information that a plant cell uses for growth and activities.
a. golgi b. vacuole c. chromosomes d. chloroplasts
The part that contains the information that a plant cell uses for growth and activities is known as Chromosome. Thus, the correct option for this question is C.
What are Chromosomes?Chromosomes may be defined as thread-like structures that appear during cell division. These structures are present in the nucleus of the cell and are made up of DNA, RNA, histones, and some non-histone proteins.
Chromosomes were first discovered by E. Strasburger in 1875. But the term chromosome was given by Waldeyer in 1888. Ultimately, the nucleus of the cell contains all sorts of genetic information which are essential for the growth and activities of organisms.
The Nucleus contains DNA which is known as the genetic material of most organisms including plants.
Therefore, a chromosome is a part that contains the information that a plant cell uses for growth and activities. Thus, the correct option for this question is C.
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Calculate the percent composition by mass of each element in NaClO2.
Answer: Divide the mass of the first dissolved component by the solution mass, and then multiply the result by 100 to calculate the mass percentage. In our example, the first dissolved compound is NaCl; the mass percent is (10 g / 136 g) x 100 percent = 7.35 percent.
Explanation: its up, look
6. Which of the following is a binary compound?
a. CaCO3
b. CuSO4
c. H2O
d. Pb(NO3)2
Answer:
The answer to your question is c. H2O
Explanation:
a. CaCO3 ----> Calcium Carbonate is obviously not a binary compound because it contains more than two elements.
b. CuSO4 ----> CuSO4 stands for copper(II) sulfate. Sulfate is the polyatomic ion SO4 -2.
c. H2O ----> Binary molecular compounds are composed of only two elements. Examples are H2O, NO, SF6 etc.
d. Pb(NO3)2 ----> Lead(II) nitrate is an inorganic compound with the chemical formula Pb(NO3)2.
I hope this helps and have a great day!
How do we determine the volume of an irreguler shaped object?
Answer:
You can measure the displacement when the object is placed in a certain volume of water.
1. ___is the speed and direction of movement.
1 Acceleration
2Density
3Velocity
4Work
Answer:
VELOCITY
Explanation:
VELOCITY IS THE SPEED AND DIRECTION OF MOVEMENT
Explanation:
velocity
reason: The velocity of an object is the rate of change of its position with respect to a frame of reference, and is a function of time. Velocity is equivalent to a specification of an object's speed and direction of motion (e.g. 60 km/h to the north).
Question 116 g of sunflower oil is
used in a recipe. The density of the
oil is 0.925 g/mL. What is the volume
of the sunflower oil in mL?
Explanation:
Volume = mass ÷ density
= 116 g ÷ 0.925 g/mL
= 125.41 mL
A 116 g of sunflower oil of 0.925 g/mL has a volume of 125.41 mL.Hydrogen sulfide gas is combusted with oxygen gas to produce sulfur dioxide gas and water vapour. If there is 48.4 L of oxygen available. What volume of hydrogen sulfide gas may be combusted if the pressure and temperature are held constant?
Answer:
2H2S + 3O2 → 2SO2 + 2H2O
V(O2) = 48.4 L
p = 105 kPa = 1.036 atm
T = 190 + 273 = 463 K
Ideal gas law:
pV = nRT
n = \frac{pV}{RT}n=
RT
pV
R = 0.08206 L×atm/mol×K
n(O2) = \frac{1.036 \times 48.4}{0.08206 \times 463}=1.319 \; mol=
0.08206×463
1.036×48.4
=1.319mol
According to the reaction:
n(H2S) = \frac{2}{3}
3
2
n(O2) = \frac{2}{3} \times 1.319 = 0.8798 \;mol
3
2
×1.319=0.8798mol
V = \frac{nRT}{p} \\ V(H_2S) = \frac{0.8798 \times 0.08206 \times 463}{1.036}=32.26 \;LV=
p
nRT
V(H
2
S)=
1.036
0.8798×0.08206×463
=32.26L
Answer: 32.26 L
Explanation:
Why is carbon an element and not a compound?
A. Carbon bonds easily with oxygen, but not helium.
B. All carbon atoms have the same number of protons.
o C. All carbon atoms have the same number of neutrons.
.
D. Carbon is found in all living organisms.
Answer:
Carbon is found in all living organisms.
Answer: d
Explanation: i promise I've took the k-12 test
What is the element name for mg2SiO4
Answer:
forsterite
Explanation:
The formula of alkanes contain 3 5 7 and 9 carbon atoms
Explanation:
In organic chemistry, an alkane, or paraffin (a historical trivial name that also has other meanings), is an acyclic saturated hydrocarbon. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in which all the carbon–carbon bonds are single.
a sheet of pure aluminum loses heat. what will happen to the aluminum atoms
Answer:
they will slow down i think
Explanation:
losing heat means it cools down so atoms are slower
2. Differentiate the types of tectonic plates.
There are three main types of plate boundaries:
Convergent boundaries: where two plates are colliding. Subduction zones occur when one or both of the tectonic plates are composed of oceanic crust. ...
Divergent boundaries – where two plates are moving apart. ...
Transform boundaries – where plates slide each other.
sorry pag mali ...Answer:
Convergent boundaries: where two plates are colliding. Subduction zones occur when one or both of the tectonic plates are composed of oceanic crust. ...
Divergent boundaries – where two plates are moving apart. ...
Transform boundaries – where plates slide passed each other.
Explanation:
3. If you drive for 3 hours at a constant speed and make it 400 miles, how fast did you go?
Answer:
133.333333333 mph
or
214.5791999994464 kph
Explanation:
Answer:133.333333333 mph
or
214.5791999994464 kph
Explanation:
what type of carbohydrates provide the body with a sustained release of energy?
Answer:
Fiber-rich, complex carbs
Complex carbs with fiber take much longer to digest than simple carbs. This helps to maintain stable blood sugar levels because sugar enters the bloodstream gradually . Complex carbohydrates provide sustained energy and help you feel fuller for longer because they are digested more slowly.
Which form of carbohydrates can your body use for energy?Glucose, also known as blood sugar, is the primary energy source for your body's cells, tissues, and organs. Glucose can be used right away or stored for later use in the liver and muscles.Carbohydrates are the body's preferred fuel source because they can be quickly converted to glucose. A light carbohydrate snack right before exercise is a good idea for quick energy. Eat protein with carbs to slow the rate at which your body absorbs them for longer-lasting energy.Fat is the most concentrated source of energy in the body, providing more than twice the potential energy of carbohydrate or protein (9 calories per gram versus 4 calories each per gram).To learn more about : Glucose
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what are 5 different bases for birds
Answer:
adenine, guanine, cytosine, thymine, and uracil
Predict the ions that form when magnesium(group IIA) and nitrogen (group VA) react:.
Answer: Mg²⁺ & N³⁻
Explanation:
Since Magnesium is in group 2, then it favors losing two electrons forming a cation with a charge of +2 ( Mg²⁺).
Since Nitrogen is in group VA, it favors gaining three electrons forming the anion with charge -3 (N³⁻).
why are some substances such as magnesium and fluoride allowed in drinking water?
Answer:Pure water does not contain fluoride, but much drinking water does contain fluoride that is deliberately added to reduce tooth decay of children who drink the water. Some drinking water supplies also contain fluoride naturally.
Explanation:
in small doses not harmful
Fluoride is a chemical that is intentionally added to drinking water in order to prevent tooth decay in children. Pure water does not naturally contain fluoride. Some sources of drinking water naturally contain fluoride as well.
Why magnesium and fluoride allowed in drinking water?Fluoride is a chemical that is intentionally added to drinking water in order to prevent tooth decay in children. Pure water does not naturally contain fluoride. Some sources of drinking water naturally contain fluoride as well.
Compared to magnesium found in food, magnesium in water is present as hydrated ions, which are more easily absorbed. Thus, the role played by water magnesium in the prevention of magnesium insufficiency may be quite important for people who drink water with high magnesium levels.
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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.
Someone pls help me I will make you brain
c- i and iii
I hope this helps
Why do planets orbit faster as they get closer to the Sun?
The orbit becomes smaller closer to the Sun.
The orbit becomes smaller closer to the Sun.
The eccentricity changes as the planet gets closer to the Sun.
The eccentricity changes as the planet gets closer to the Sun.
The force of gravity increases closer to the Sun.
The force of gravity increases closer to the Sun.
The Sun's magnetism causes a "sling shot" effect.
Explanation:
The speed at which a planet orbits the Sun changes depending upon how far it is from the Sun. When a planet is closer to the Sun the Sun’s gravitational pull is stronger, so the planet moves faster. When a planet is further away from the sun the Sun’s gravitational pull is weaker, so the planet moves slower in its orbit.
which group of elements would react with lithium
Explanation:
lithium has group 1 elements and it valance electron has 1
so it more react with group 7 to be more stable
Name each compound
NaF
K2CO3
….
How do the claims in drug ads impact the medical profession in 4 sentence
Answer:
But drug advertising is not all about deception. It can offer helpful information if you know what to look for. "Advertisements can offer information on drugs that may help many older men, especially those who have conditions that may be tough to treat or manage, such as diabetes and hypertension,"
a reaction is said to be ________ if the bonds formed during the reaction are stronger than the bonds broken.
Answer:
Exothermic
Explanation:
Bond strength has everything to do with the energy associated with it. What I mean by that, is a stronger bond will require a lot higher of an energy input to break than a weaker bond.
In the same way, energy is released when a bond is made. So, the formation of a stronger bond releases more energy than the formation of a weaker bond.
So, putting the two ideas together, if the bonds formed as stronger than the bonds broken, then more energy is released than taken in, which means energy is released overall over the course of the reaction. This means that the reaction is exothermic.
If there was energy taken in overall, this would be an endothermic reaction.
Let me know if that makes sense, and hope I helped! :)
Exothermic reaction is a reaction in which the bonds formed during the reaction are stronger than the bonds broken.
When chemical reactions occur, there will always be an accompanying energy change.
In exothermic reaction the bonds formed in the products are stronger than the bonds broken in the reactants whereas in endothermic reaction the bonds broken in the reactants are stronger than the bonds formed in the products.
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A car moves with a velocity of 15 m/s west for 3 seconds. Then, the
car moves with a velocity of 15 m/s east for 1 second. What is the
total displacement of the car?
Answer:
450 metre
Explanation:
VELOCITY = DISPLACEMENT /TIME TAKEN. THEREFORE THE DISPLACEMENT = 450 M.
Explanation: