In hydrogen, in order for an electron to emit visible light, it must fall from
some energy state and stop where?
A. 1st energy level
B. 2nd energy level
C. 3rd energy level
D. 4th energy level
Answer:
B
Explanation:
What are similarities and differences between a falling object and a pendulum?
Answer:
The similarity is that they both follow the laws of physics.
In both cases, the motion is opposed by the medium where the object presses through the medium and forces it to part and flow around the object. This creates friction.
If an object is smooth and pointed like a bomb, the friction is minimised. If it is rough with pockets or vertical flat surfaces, the friction is maximised. A parachute presents a round hollow cup face to the flow, maximising friction. This is due to a hole in the top of the parachute.
The difference is the power source. In the vertical direction it is generated by gravity, the force created by the planet. This force is opposed not only by friction but also the difference between the density of the object and the medium surrounding it. If there is a large difference then the acceleration will be large and a high percentage of g.
For example we have a density of 1000 kg/meters cubed and air has a density of 1 Kg per meters cubed, the difference is 999, so we fall at an acceleration of 999/1000 x g. minus the effects of friction.
In the horizontal direction, gravity still opposes the movement creating friction in the vertical direction such as dragging a heavy object on the floor behind you. Force needs to be created horizontally to oppose the friction and to create an acceleration. A balance is soon reached where the acceleration stops and the object is dragged at a constant velocity.
The speed of sound through air at 20°C is 343 meters per second. The speed of sound through fresh water at 20°C is 1,482 meters per second.
Which of the following could be the speed of sound through solid steel?
A.
1,370 meters per second
B.
353 meters per second
C.
5,960 meters per second
D.
145 meters per second
Answer:
C. 5960 meters per second
Whats molecular formula of 26,4% carbon , 3,3 % Hydrogen and 70,3% oxygen?
Explanation: Therefore the molecular formula is twice the empirical formula: C2H6O2. The compound dioxane contains only carbon, hydrogen, and oxygen. When 0.956 g dioxane is burned, 1.91 g carbon dioxide and 0.782 g water are formed. In another experiment, it was determined that 6.04x10-3 mol dioxane weighs 0.532 g.
If I perform a dilution, which is true? *
volume of solvent decreases
volume of solution increases
amount of solute increases
amount of solute decreases
Answer:
Amount of solute decreases
Explanation:
Since during dilution, the solute dissolves on the solvent hence its amount decreases.
Part A
Choose the paramagnetic species from below.
O He
O Te
O T14+
O All of the above are paramagnetic.
None of the above is paramagnetic.
Answer:
o He
Explanation:
basyshsiz0qnshshhsjzz
16. What is the typical diameter of an atom?
A. | 10-14 m
B. I x 10-12 m
C. | 10-10 m
D. | x 10-8 m
HELPP PLSS
what is meant by chemical combination? what are the laws of chemical combination?
Answer:
In simple terms, this law states that matter can neither be created nor destroyed. In other words, the total mass, that is, the sum of the mass of reacting mixture and the products formed remains constant.
Explanation:
please give me brain list and follow
what part of the food chain is a mink
a: secondary consumer
b: primary consumer
c:prouducer
d:herbivore
Answer: A secondary consumers
Explanation:
They are carnivores, feeding on primary consumers. The Bobcat, Raccoon, Mink, and Bass are all secondary consumers.
When aqueous ammonia is added to a solution containing Bi3+ and Cu2+ cations, ____________ occurs. A. Reduction to black bismuth metal.B. Precipitation of a black bismuth hydroxide.C. Precipitation of white bismuth hydroxide. D. Formation of a red-brown precipitate of Cu2[Fe(CN)6].
Answer:
C. Precipitation of white bismuth hydroxide.
Explanation:
When aqueous ammonia is added to a solution that has Bi3+ and CU2+ cations, what we would have as a chemical result is the precipitation of white Bismuth hydroxide.
The chemical reaction for this can be written as,
Bi3+ + 2NH3 + 3H2O ⇌ Bi(OH)3(s) + 3NH4
Thank you!
When you take off a wool hat, some of the electrons from your hair transfer to
the hat. When this happens, your hair can stand up on end. Why doesn't
gravity hold your hair down?
A. The distance to the center of Earth is vastly larger than between
the hat and your hair,
B. The electrical field caused by the charged hair disrupts the
gravitational field near your hair
C. The electrostatic force is stronger than the gravitational force
between Earth and your hair,
D. The gravitational force between the hat and your hair opposes
Earth's gravitational force,
Answer:
C. The electrostatic force is stronger than the gravitational force
between Earth and your hair
Explanation:
Electrostatic forces are extremely strong. When your hair becomes charged from the electrons, it causes the strands of your hair to repel (push away) from each other because they have like (the same) charges.
pleaseeeee helpppp!!!!!!
Answer:
90% of people marry there 7th grade love. since u have read this, u will be told good news tonight. if u don't pass this on nine comments your worst week starts now this isn't fake. apparently if u copy and paste this on ten comments in the next ten minutes you will have the best day of your life tomorrow. you will either get kissed or asked out in the next 53 minutes someone will say i love u
How many mL of 0.25 M NaOH would have 0.18 moles of NaOH
Answer:
[tex]720\ \text{mL}[/tex]
Explanation:
M = Molarity of NaOH = 0.25 M = 0.25 mol/L
n = Number of moles of NaOH = 0.18 moles
Volume of solution is given by
[tex]V=\dfrac{n}{M}[/tex]
[tex]\Rightarrow V=\dfrac{0.18}{0.25}[/tex]
[tex]\Rightarrow V=0.72\ \text{L}\times 10^3=720\ \text{mL}[/tex]
The volume of NaOH in the solution is [tex]720\ \text{mL}[/tex].
What is the percent yield of LiCl if I produced 30.85g LiCl and my theoretical yield was calculated to be 35.40g LiCl?
Answer:
87.15%
Explanation:
To find percent yield, we can use this simple equation
[tex]\frac{Actual}{Theoretical} *100[/tex]
Where "Actual" is the amount in grams actually collected from the reaction, and "Theoretical" is, well, the theoretical amount that should have been produced.
They give us these values, so to find the percent yield, just plug the numbers in.
[tex]\frac{30.85}{35.40} *100\\\\ =87.15[/tex]
So, the percent yield is 87.15%
An easy trick to remember how to do this is just to divide the smaller number by the bigger number and move the decimal back two places. If you have a percent yield greater than 100%, something is wrong in the reaction.
In the following reaction:
C6H6 + Br2 → C6H5Br + HBr
Assume 1.25 moles of C6H6 react with sufficient bromine, how many moles of C6H5Br should form?
2.50 mol
5.00 mol
0.625 mol
1.25 mol
Answer:
1.25mol
Explanation:
The equation you gave is balanced and everything is in a 1:1:1:1 ratio. Because there is excess bromine, the reaction can proceed until completion which will give you 1.25 mol C6H5Br
how does a spectral signature help scientists determine the composition of planets and other stars???
Answer:
How do scientists determine the chemical compositions of the planets and stars? Each element absorbs light at specific wavelengths unique to that atom. When astronomers look at an object's spectrum, they can determine its composition based on these wavelengths. ... That fingerprint often appears as the absorption of light.
Explanation:
We can conduct different spectroscopic techniques for the sample collected from stars and planets to determine their composition. Using these techniques, scientists can identify the compounds and elements present in them.
What are spectroscopic techniques ?There are various spectroscopic techniques such as IR spectroscopy, UV- visible spectroscopy, mass spectroscopy etc. to determine the composition of both inorganic and organic compounds.
The IR spectroscopy uses the vibrational transitions of molecules by the absorption of IR radiation. The stretching or bending frequency of each functional groups are characteristic to them. Hence, we can determine the functional groups present in the molecules.
Similarly mass spectrum, atomic emission spectrum etc. provide valuable information about the sample under study including their mass and elemental compositions. Hence, spectral signature definitely helpful to determine the composition in stars and planets.
Find more on spectroscopy:
https://brainly.com/question/30256292
#SPJ6
Wch of the following phrases is the best definition of science?
A. Research that determines the behavior of the physical world
B. Observation of the physical world
C. Knowledge that governs the physical world
D. A set of predictions that interpret patterns in the physical world
please help!!! I have to submit this in a few!!!
Answer:
c
Explanation:
A student pours 800.0 mL of a 3.000 molar solution of sodium hydroxide into a 2.00 liter volumetric flask and fills the flask up with water. What is the new molarity of the solution?
A) 12.00 M
B) 1.20 M
C) 14.00 M
D) 0.0750 M
Select the correct algebraic form for the equation to be used for this calculation.
n equals StartFraction R T over P V EndFraction.
n equals StartFraction P V over R T EndFraction.
n equals StartFraction R V over P T EndFraction.
Answer:
55.9 kPa
Explanation:
What part of the food chain is a mink?
Answer:
The minks are very high on the aquatic food chain. The mink is a carnivorous animal, which means it eats only meat.
Explanation:
Answer:
The minks are very high on the aquatic food chain. The mink is a carnivorous animal, which means it eats only meat.
Helpppp me pleaseeee now I’ve been struggling so bad w this
Answer:
I don't know what the passage says, but I feel like the most logical conclusion is D or the last one.
Explanation:
Answer:
D! Hope this helps! Figured id help with all of ur questions!
Explanation:
Im a wiz at science! ;)
Which one of the following is an example of a balanced chemical reaction?
A
C3H60 + 30 2 + 3C0 2 + 3H 20
B 2C 3H 60 + 90 2+ 6CO2 + 6H 20
© C3H60 +90 2 +300 2 +3H 20
D) 2C 3H 60 + 90 2+ 6CO2 + 3H 20
C3H 60 + 40 2 + 3CO 2 + 3H 20
An example of a balanced chemical reaction (equation) is: D. [tex]C_3H_60 + 40_2[/tex] ----> [tex]3CO_2 + 3H_20[/tex]
In Chemistry, a chemical equation is typically used to denote or represent the chemical reaction between two or more chemical elements.
A balanced chemical equation can be defined as a chemical equation wherein the number of atoms on the reactant (left) side is equal to the number of atoms on the product (right) side.
This ultimately implies that, both the charge on each atom and sum of the masses of the chemical compounds or elements in a chemical equation are properly balanced.
Ideally, the first step in balancing a chemical equation is to count the number of atoms in the reactant and product side.
[tex]C_3H_60 + 40_2[/tex] ----> [tex]3CO_2 + 3H_20[/tex]
For reactants:
Carbon = 3 atoms.Hydrogen = 6 atoms.Oxygen = 1 + 8 = 9 atoms.For products:
Carbon = 3 atoms.Hydrogen = 6 atoms.Oxygen = 6 + 3 = 9 atoms.Since, the number of atoms on the reactant (left) side is equal to the number of atoms on the product (right) side, this is an example of a balanced chemical reaction (equation).
Read more: https://brainly.com/question/13750908
What is the 11th element in period 4?
plz don't send me another tiny link
Answer: According to my ggle search its Copper!
Explanation:
Explanation:
sodium is the 11thPredict the shape of the molecule.....
Answer:
bent
Explanation:
Which type of light would make an object appear larger and closer?
Answer:
A convex lens bends light rays inward, which results in the object being perceived as larger or closer.
Explanation:
The light ray refracted from an object may look different based on how they bends light and at what angle. Convex lens bends light inwards and the refracted light appear closer and bigger whereas, a concave lens makes light ray away and smaller.
What is refraction?Refraction is the optical phenomenon by which a light ray bends in its direction when passing from one medium to the other. For instance light ray bends when it pass from air to water or air to glass and vice versa.
The measure of bending of light in a medium is called refractive index of that medium. Refraction makes the object appear to be closer sometimes such as in water when light bends in direction.
When light refracts from convex lens, the bending is inwards and the object is perceived to be closer and larger. Whereas, a concave lens make the bending outwards where the object appeared to be smaller and far.
To find more on refraction, refer here:
https://brainly.com/question/14760207
#SPJ2
Describe the motion of molecules in these two
substances when the ice cube is placed on the
radiator.
Answer:
When in direct contact, the fast-moving molecules in the radiator collide with the slow-moving molecules in the ice cube. Kinetic energy is transferred from the molecules in the radiator to the molecules in the ice cube, causing a slowdown of the radiator molecules and an acceleration of the ice molecules.
Explanation:
Answer
when in direct contact, the fast-moving molecules in the radiator collide with the slow-moving molecules in the ice cube. Kinetic energy is transferred from the molecules in the radiator to the molecules in the ice cube, causing a slowdown of the radiator molecules and an acceleration of the ice molecules.
Explanation:
Please help!!! I will mark you brainiest!!!
Answer:
Some positive effects of using synthetic plastic is that scientist can make it softer and biodegradable so that nature can break it down and destroy it so it won't affect the environment. And scientist can also make stronger and tougher in products so they can last longer.
Explanation:
5) A scientist adds 1.2 liters of water to a 5.0 liter solution, causing the molarity to become 0.4 M. What was the molarity of the initial solution before the dilution?
Explanation:
i hope i helped you in this problem
According to the molar concentration, the molarity of the initial solution before the dilution is 0.096 M.
What is molar concentration?Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.
The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.
In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.Substitution of values in formula M₁V₁=M₂V₂ gives M₁= 0.4×1.2/5=0.096 M.
Thus, the molarity of the initial solution before the dilution is 0.096 M.
Learn more about molar concentration,here:
https://brainly.com/question/15532279
#SPJ7
Help me I’m struggling with this one
Answer:
Eukarya
Explanation:
It's larger than a prokaryotic cell and it has a nucleus.