Some materials are phosphorescent, meaning that they can absorb light energy from the Sun, and then re-emit this energy later. Many objects people use today are phosphorescent, including glow-in-the-dark plastics. Some plastic objects have phosphorescent materials in them, which causes them to glow after they are exposed to light. In 1896, one year after x-rays were discovered, scientist Henri Becquerel hypothesized that uranium might work in this way as well. So he exposed a sample of uranium to sunlight, and then was pleased to discover that the uranium continued to emit energy even after it was taken out of the light. However, after several straight days of cloudy skies over his laboratory, Becquerel was shocked to discover that the energy kept coming from the uranium, even without sunlight. What had Becquerel accidentally discovered?

Answers

Answer 1

Answer:

Explanation:

After the Becquerel came to know the discovery of X-ray by Roentgen  Becquerel began looking for a connection between the phosphorescence  and the newly discovered X-rays. His thought was that phosphorescent uranium salts might absorb sunlight and reemit it as x rays.

To experiment this  he exposed a sample of uranium to sunlight, and then was pleased to discover that the uranium continued to emit energy even after it was taken out of the light. However, after several straight days of cloudy skies over his laboratory, Becquerel was shocked to discover that the energy kept coming from the uranium,  

He reported that the uranium salts emitted radiation without any stimulation from sunlight.  He did further tests to confirm that sunlight was indeed unnecessary, that the uranium salts emitted the radiation on their own.

Initially he thought the effect was due to particularly long-lasting phosphorescence, but he soon discovered that non-phosphorescent uranium compounds exhibited the same effect. After that he announced that the element uranium was indeed what was emitting the radiation.  

At first he also believed his rays were similar to x-rays, but his further experiments showed that unlike x-rays, which are neutral, his rays could be deflected by electric or magnetic fields which was against his expectations. Finally “Radioactivity” term was given to describe this new phenomenon.

This story of becquerel is well known example of accidental discovery.


Related Questions

Which statement accurately describes the products of a reaction?
A: melting of a substance
B: a change in color of a substance
C: freezing of a substance
D: boiling of a substance

Answers

B, A change in color of a substance what ever the substance was it had a reaction of changing color

Answer:

B: a changing in color of a substance

Explanation:

The answer is B because whatever substance you get it would have a reaction of color

Explain a limiting factor for each location in the South America Ecosystems Interactive

Answers

Hey sorry I didn’t get to you y’all I can get it a few hours ago and I’m going back with you soon

Answer:

just getting 5 points

Explanation:

At -15°C, water is a:
solid,liquid,gas

Answers

Answer:

Water is a solid.

Explanation:

Water freezes at 0° C, or 32°F.

Please mark me Brainliest, I need it to move onto the next level.

Answer the Question where it says, “Model It!” Thank You! Really Appreciate It! :)

Answers

Answer: Thx for the free points brother!

Explanation: Thx!

A measurement must have a ________________ and ___________________ to be concerned correct.

Answers

Answer:

Explanation:

grips with three basic problems: error; representation, which is the justification of number …

Anymore info on the question?

A drop in the water table produced when water is
overpumped from a well, is called

Answers

Answer:

I feel stupid saying this but a spring??

Explanation:

Sorry it was only a guess

A scientist plants two rows for experimentation. She puts fertilizer on row 1 but does not put fertilizer on row 2. Both rows receive the same amount of water and light intensity. She checks the height of the corn growth over the course of 5 months. What is a constant in this experiment?

Answers

Answer:

Water and light intensity

Explanation:

In an experiment, the component parts of the experiment usually includes a variable which is of two types- independent variable, dependent variable; a constant and a control.

An independent variable is the part of the experiment the person changes or controls.

The dependent variable is the part of the experiment that changes due to changes being made to the independent variable.

The control group is a part of the experiment in which all variable factors have been kept constant and which is used as a standard to compare with other trials of the experiment.

A constant is the part or factor which do not change and is kept constant during the experiment.

In the experiment conducted by the scientist, the two rows of plant receives the same amount of water and light intensity, therefore, they are both the constants.

El cloro es un elemento capital en la potabilización del agua. A la natura se han encontrado dos isótopos del cloro, 35Cl y 37Cl. Indica los parecidos y diferencias entre estos dos isótopos si los átomos se encuentran en un estado eléctricamente neutro.

Answers

Answer:

I cant understand. Can you translate it to english?

Will give brainliest !

Answers

Answer:

C

Explanation:

I don't have this class but I'm 99.9% sure it's C. :)

PLEASE HELP!!!! ANSWER 2 QUESTIONS FOR 50 POINTS AND BRAINLIEST!

Answers

1)to see how the food coloring affected each amount of water
2)the amount of water in each cup caused the food coloring to spread either faster or slower

Sodium combines with water to produce sodium hydroxide and hydrogen gas. Which word equation represents this violent reaction? sodium hydroxide + water Right arrow. Sodium + hydrogen sodium + water Right arrow. Sodium hydroxide + hydrogen sodium + hydrogen Right arrow. Sodium hydroxide + water sodium + sodium hydroxide Right arrow. Water + hydrogen

Answers

Answer:

 

Explanation:

When Sodium reacts with water it forms Sodium hydroxide and hydrogen gas. Sodium being a alkali metal reacts violently with water and catches fire during this reaction

word equation

[tex]Sodium+Water[/tex]→[tex]Sodium Hydroxide+ hydrogen gas[/tex]

Chemically

[tex]2Na(s) + 2H2O[/tex]→[tex]2NaOH(aq) + H2(g)[/tex]

Sodium hydroxide and hydrogen gas are formed when sodium combines with water. As an alkali metal, sodium interacts violently with water, catching fire in the process.

Word equation:-

Sodium+Water →Sodium hydroxide+hydrogen

Chemically, the reaction is as follows:-

[tex]2Na+2H_2O\rightarrow2NaOH+H_2[/tex]

Na-Sodium

[tex]H_2O[/tex]-Water

NaOH-Sodium hydroxide

[tex]H_2[/tex]-hydrogen

Hence, the word equation is:-

Sodium+water Right arrow Sodium hydroxide+hydrogen

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What is the reaction ship between cells and tissues

Answers

Answer:

the answer is a bc tissues are a bunch of cells clumped together and tissues make up organs

Explanation:

Which statement is true?
A.
A molecule having a covalent bond can be ionic.
B.
A molecule having a covalent bond is always polar.
C.
A molecule having a covalent bond may be polar or nonpolar.
D.
A molecule having a covalent bond is always nonpolar.

Answers

Answer:

c) A molecule having a Covalent bond may be polar or non polar

What is the name of Na2CO3

Answers

Answer:

its sodium carbonate

Explanation:

Answer:

Explanation:

you just said it Na2CO3

which base-pair rules apply to the double helix structure?

SELECT ALL THAT APPLY

a. A-G
b. G-T
c. A-T
d. C-G

Answers

This is definitely more biology. Double helix represents DNA not RNA.
Adenine always pairs with thymine.
Cytosine will always pair with guanine.
So answers C and D.
The reason they pair together is because of the way they can form hydrogen bonds with one another.

Fritz Haber, a German chemist, discovered a way to synthesize ammonia gas (NH3) by combining hydrogen and nitrogen gases according to the following equation:

3H2(g) + N2(g) → 2NH3(g)

What volume of nitrogen is needed to produce 250.0 L of ammonia gas at STP?
L
What volume of hydrogen is needed to produce 2.50 mol NH3 at STP?
L

Answers

Answer:

Volume of nitrogen needed  = 125.5 L

Volume of hydrogen needed = 84.05 L

Explanation:

Given data:

Volume of ammonia produced = 250.0 L

Volume of nitrogen needed = ?

Solution:

Chemical equation:

N₂ + 3H₂  →    2NH₃

Number of moles of ammonia:

PV = nRT

1 atm× 250.0 L = n × 0.0821 amt.L/mol.K × 273K

250.0 atm.L = n × 22.41 amt.L/mol

n = 250.0 atm.L /22.41 amt.L/mol

n = 11.2 mol

Now we will compare the moles of ammonia with nitrogen.

             NH₃          :           N₂

               2             :            1

             11.2            :         1/2×11.2 = 5.6 mol

Volume of nitrogen needed:

PV = nRT

1 atm× V  = 5.6 mol × 0.0821 amt.L/mol.K × 273K

V  = 125.5amt.L/1 atm

V = 125.5 L

2nd)

Given data:

Number of moles of ammonia produced = 2.50 mol

Volume of hydrogen needed = ?

Solution:

Chemical equation:

N₂ + 3H₂  →    2NH₃

Now we will compare the moles of ammonia and hydrogen.

                     NH₃          :          H₂

                       2            :            3

                    2.50         :           3/2×2.50 = 3.75 mol    

Volume of hydrogen:

PV = nRT

1 atm × V = 3.75 mol × 0.0821 amt.L/mol.K × 273K

V = 84.05 amt.L/1 atm

V = 84.05 L

 

             

what is the periodic table and what does it mean elements???​

Answers

Answer:

The periodic table is a tabular array of the chemical elements organized by atomic number, from the element with the lowest atomic number, hydrogen, to the element with the highest atomic number, oganesson. The atomic number of an element is the number of protons in the nucleus of an atom of that element.

Explanation:

answer:

what is the periodic table?

the the periodic table is:

basically an arragement all of the of the chemical elements organized by atomic number, from the element with the lowest atomic number, (hydrogen), to the element with the highest atomic number, (oganesson).

what are elements?

elements are:

a substance that is made entirely from one type of atom.

example: the element hydrogen is made from atoms containing a single proton and a single electron. if you change the number of protons an atom has, you change the type of element it is.

explanation:

i answered your questions & hope you have a great day!

pls give me brainliest <3

Which element has a larger atomic radius than sulfur? O chlorine O cadmium fluorine oxygen​

Answers

Answer: solo necesito puntos lo siento

Explanation:

Answer:

Cadmium has larger atomic radius than sulfur.

Explanation:

Down a period, atomic radii decrease from left to right due to the increase in the number of protons and electrons across a period: when a proton is added the pull of the electrons towards the nucleus is larger, so the size of the atom decreases.

Hence, you can compare the elements that belong to a same period and predict that the atom with lower atomic number (number of protons) will haver larger atomic radius. With that:

Oxygen and fluorine are in the period 3, being oxygen to the left of fluorine, so oxygen is larger than fluorine.

Sulfur and chlorine are in the period 4, being sulfur to the left of chlorine, so sulfur is larger than chlorine.

Now see whan happens down a group. Atomic radius increases from top to bottom within a group due to electron shielding. That permits you to compare the size of the elements in a group:

Fluorine and chlorine are in the same group (17), with chlorine directly below fluorine, so the atomic radius of chlorine is larger than the atomic radius of fluorine.

Sulfur and oxygen are in the same group (16), with sulfur directlly below oxygen, so sulfur the atomic radius of sulfur is larger than the atocmi radius of oxygen.

So far, you can rank the atomic radius of sulfur, chlorine, fluorine, and oxygen, in increasing order as:

O < F < Cl < S, concluding that O, F, and Cl have smaller atomic radius than S.

Cadmiun, Cd, is to the left and below sulfur, so both electron shielding (down a group) and increase of the number of protons (down a period) lead to predict the cadmium has a larger atomic radius than sulfur.

the average mass of all the isotopes of an element is called the ______________.

will mark brainlest for the best answer.

good luck

Answers

Answer:

atomic mass

Explanation:

the avergae mass of all the isotopes of an element is called the atomic mass. the atomic mass is the mass of an atom.

The answer is Atomic Mass.

the mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.

Why does the compass needle move when the compass is placed near the wire?

Answers

Answer:

it moves because the wire is metal and when metal is near a compass it throughs off the direction because metal has its own magnetism.

Explanation:

I hope this helps.

3 questions for branliest!! Please help.
1. Noble Gas with the largest radius?
2. Least electronegative of the halogens? (not astatine)
3. What element is 1s2 2s2 2p6 3s2?

Answers

1. Ununoctium
2. Ununseptium
3. Magnesium

Can some please help me understand what this means!!
Write the electron configurations of the following elements. Only write them as noble gas or full if it states to do so.

1. Phosphorus (P) Full configuration : ______________________________________________

2. Ruthenium (Ru) Full configuration : _____________________________________________

3. Barium (Ba) Noble gas configuration : ____________________________________________

4. Thorium (Th) Noble gas configuration : ___________________________________________

Answers

Answer: Phosporus- 1s2 2s2 2p6 3s2 2p3

Ruthenium- 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d6

Barium- (Xe)6s2

Thorium- (Rn) 6d2 7s2

Which type of waves travel faster gamma or radio

Answers

Answer:

radio

Explanation:

Among electromagnetic waves, UV rays are most dangerous because exposure to these radiation cause serious problems in living organism. Radio wave travel faster than gamma wave.

What is electromagnetic wave?

Electromagnetic wave is a wave which contain two component one is electric component and other is magnetic component. The electric and magnetic component are perpendicular to each other. There are so many wave that comes under electromagnetic wave like infrared wave , radio wave.

There is a relation between energy of wave. frequency of wave, and wavelength of wave

Mathematically,

E=hc/λ

where,

E = energy of electromagnetic wave

h is planks constant having value 6.67×10⁻³⁴js

c is speed of light that is 3×10⁸m/s

λ is the wavelength of electromagnetic wave

Therefore, radio wave travel faster than gamma wave.

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Which of the following identifies a type of electromagnetic radiation with a higher frequency than Microwaves but a lower frequency than Ultraviolet waves?


Radio waves


X-rays waves


Gamma waves


Infrared waves

Answers

Answer:

infrared

Explanation:

it goes (in increasing order)

radio

microwave

infared

visible light

ultraviolet

xray

gamma ray

The infrared radiation in the electromagnetic spectrum is come in between ultraviolet waves and microwaves. It have high frequency than microwave and low frequency than UV rays. Thus option D is correct.

What is electromagnetic spectrum?

Electromagnetic spectrum is the arrangement of different radiations in the order of increasing frequency or increasing energy thus in the decreasing order of wavelength.

The longer wave is radio waves with lowest energy and then microwave after that infrared waves are arranged in the spectrum. Thus next from visible light to UV, gamma and x-rays energy and frequency increases.

Higher wavelength radiations are less powerful but travel more distance where as shorter waves are more powerful but travel less. Thus, the radiation have less frequency than UV rays but high frequency than microwave is Infrared rays. Option D is correct.

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BRAINLIEST TOTHE CORRECT ANSWER!!! Why is C6H12O6 not considered to be an empirical formula for glucose?

Answers

Its molecular formula is C6H12O6. Since each of the subscripts is divisible by 6, the empirical formula for glucose is CH2O.

It´s just the way it is. Have a good day!

Its chemical structure is C[tex]_6[/tex]H[tex]_{12}[/tex]O[tex]_6[/tex]. The empirical formula that glucose is CH[tex]_2[/tex]O since every one of the subscripts being divided by 6.

What is empirical formula?

The definition of an empirical formula for a compound is one that displays the ratio of the components present in the complex but not the precise number of atoms in the molecule. Subscripts are used next to the component symbols to indicate the ratios.

If you are aware of the compound's molar mass, you may apply the equation to determine its molecular composition. Dividing the compound molar mass either by empirical formula mass after calculating the organic compound with the formula mass to get this. Its chemical structure is C[tex]_6[/tex]H[tex]_{12}[/tex]O[tex]_6[/tex]. The empirical formula that glucose is CH[tex]_2[/tex]O since every one of the subscripts being divided by 6.

Therefore, the empirical formula that glucose is CH[tex]_2[/tex]O since every one of the subscripts being divided by 6.

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When you stir sugar into your tea with a spoon, the tea keeps swirling
even after you take your spoon out. *
which law of motion is it?

Answers

The first law of motion

When you stir sugar into your tea with a spoon, the tea keeps swirling

even after you take your spoon out.This is first law of motion.

What is motion?

Motion is defined as a phenomenon which is described with respect to change in object's position with respect to time.It is given in terms of displacement,velocity,distance ,acceleration,speed.

Branch of physics which deals with motion of objects without any reference to it's cause is called kinematics while the branch which studies forces and their effects on motion is called as dynamics.

Motion applies to various systems like objects,bodies, matter particles ,radiation ,curvature.There are three laws of motion which are proposed by Newton.Classical mechanics is based on Newton's law of motion.Relativistic  mechanics is based on modern kinematics.

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A mutation is a change in ___.

A. protein
B. sex cell
C. body cell
D. gene

Answers

Answer:

gene

Explanation:

brainly crown?

Answer:

D, gene

Explanation:

Mutations are abnormal changes in the DNA of a gene.

how does the concept of conservation of mass apply to chemical reactions?

Answers

Answer:

mass cannot be created nor destroyed just moved around

Explanation:

The law of conservation of mass or principle of mass conservation states that for any system closed to all transfers of matter and energy, the mass of the system must remain constant over time, as the system's mass cannot change, so quantity can neither be added nor be removed so it can only be moved around during a chemical reaction

Which is an example of mechanical weathering?
hydrated minerals
iron oxide
water moving over rocks
limestone cave formations

Answers

I think it’s water moving over rocks

The answer is water moving over rocks.

I got it right on my quiz :)

A car travels a distance of 200 meters in 10 seconds. What is the average speed of the car?

Answers

Answer:

72,000mph

Explanation:

hope this helps

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