Summarize the history of radioactivity by choosing the scientist(s) involved with each discovery.


conducted experiments with uranium-containing minerals and pure uranium.


came up with the term “radioactivity.”


showed that uranium in a mineral gave off radiation even without being exposed to the Sun.


discovered radium and polonium.


conducted experiments with fluorescent minerals and photographic plates.

Answers

Answer 1

Answer:

Marie and Pierre CurieMarie and Pierre CurieAntoine Henri BecquerelMarie and Pierre CurieAntoine Henri Becquerel

Explanation:  Correct on Edg 2020/2021.


Related Questions

what the correct answer ​

Answers

Answer:

sulfer has 6 energy levels/orbits and 16 valence electrons

The person above me said is right


Explanation:

It’s right

1.What element is located at period 3, group 13?

2.Element at group 4, period 5?

Answers

Question 1 is boron
And question 2 is Vanadium
1.) Boron and 2.) vanadium

The contents of a bucket filled from a well were in a ____ stat. If the contents were heated up enough, they would change to a ____ state.

Answers

Answer: liquid state

A gas state

Explanation:

Which of these substances has a definite volume but not a definite
shape?
A. paper
B. grass
C. juice
D. water vapor

Answers

I think answer should be b. Please give me brainlest I hope this helps let me know if it’s correct or not okay thanks

All amino acids have an amino group and
a carboxyl group.
a chloro group.
a bromo group.
a benzyl group.

Answers

Answer:

carboxyl group

Explanation:

Answer:

A EDGE 2022

Explanation:

Quick Help 10 points

If the reactants of a reaction have one S and four O atoms, what will the
products have?
A. Four S atoms and four O atoms
B. One S atom and one 0 atom
O C. Four Satoms and one o atom
O D.One S atom and four O atoms

Answers

D - matter remains constant in any chemical equation, so reactants always equal products.

Answer:

The products will have one S and four O atoms.

PLEASE HELP My perfume which used to smell pretty now smells weird after 5 years. Is
this a physical or chemical change?
A. Chemical Change
B. Physical Change

Answers

the answer is A chemical change

Answer:

The answer is a chemical change

Explanation:

Question 1
Identify the type of bonding for CaBr2

Answers

CaBr2 is an ionic bond. This is because the calcium gives up an electron to each of the chlorine atoms resulting in the calcium becoming Ca2+ ions...

5) Chlorine has 7 valence electrons. Neon has 8 valence electrons. Which on is more likely to undergo a
chemical reaction, and why?

Answers

Answer:

well, chlorine will undergo in a chemical reaction

Explanation:

neon has completed valence shells, so it neither need electron and or it also don't need to donate the electrons. hence it will not participate in any chemical reaction and it is stable in nature.

whereas chlorine need one more electron to complete it's valence shell and in order to be stable , so it will try to gain one electron , hence

it will take place in a chemical reaction

If 2.5 grams of calcium bromide reacted with excess lithium oxide, how many grams of bromide product would be formed?

Answers

Answer: 2.17 g of  bromide product would be formed

Explanation:

The reaction of calcium bromide with lithium oxide will be:

[tex]CaBr_2+Li_2O\rightarrow 2LiBr+CaO[/tex]

To calculate the moles :

[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]    

[tex]\text{Moles of calcium bromide}=\frac{2.5g}{199.9g/mol}=0.0125moles[/tex]

As lithium oxide is in excess, calcium bromide is the limiting reagent.

According to stoichiometry :

1 mole of [tex]CaBr_2[/tex] produce = 2 moles of [tex]LiBr[/tex]

Thus 0.0125 moles of [tex]CaBr_2[/tex] will require=[tex]\frac{2}{1}\times 0.0125=0.025moles[/tex]  of [tex]NH_3[/tex]

Mass of [tex]LiBr=moles\times {\text {Molar mass}}=0.025moles\times 86.8g/mol=2.17g[/tex]

Thus 2.17 g of  bromide product would be formed

Balance this equation by filling in the missing coefficient: 6 CO2 + 6 H2O + Sunlight = C6H12O6 + ?? O2
A. 1
B. 6
C. 12
D. 36

Answers

Given that,

The equation is : [tex]6CO_2+6H_2O+\text{sunlight}\rightarrow C_6H_{12}O_6+?O_2[/tex]

To find,

The missing coefficients.

Solution,

[tex]6CO_2+6H_2O+\text{sunlight}\rightarrow C_6H_{12}O_6+?O_2[/tex]

Let the value of ? is x.

It is the equation of photosynthesis.

In LHS,

Carbon atoms = 6

Hydrogen atom = 12

Oxygen atom = 18

In RHS,

Carbon atoms = 6

Hydrogen atom = 12

Oxygen atom = 6

If we make the equation as [tex]6CO_2+6H_2O+\text{sunlight}\rightarrow C_6H_{12}O_6+6O_2[/tex]

No the number of atoms in RHS = 6+ 12 = 18

It means if we take the value of ? as 6 the equation will be balanced.

Hence, the correct option is (B) "6".

A student bought a 1.55-ounce chocolate bar and left it in a car on a hot day.


How many ounces of chocolate are in the melted bar?

A.
Exactly 1.55 ounces

B.
An unknown number of ounces

C.
At least 1.55 ounces

D.
Less than 1.55 ounces

Answers

Answer:

A. Exactly 1.55 ounces

PLS HELPP!!!
i’ll mark brainliest + 15 points!!


If 2.5 grams of calcium bromide reacted with excess lithium oxide, how many grams of bromide product would be formed?

Answers

ok so this could be totally wrong because i just learned how to do this in chem but i got 2.2g. i included i picture of my work

On the periodic table, all of the elements in Group 1 are ____________
a) considered pure.
b) do not form chemical bonds.
c) have the same number of valence electrons. ​

Answers

they have the same number of valence electrons

PLEEEASSEEEE HELPPPPP!!!!!Take some time to research a utility plant. If there is one in your area, you may even visit it.
Otherwise, look up a type of plant that produces energy - such as a nuclear power plant, a
hydroelectric plant, or a coal-burning plant. Find out what energy resources are brought into the
plant. Then find out what energy and what "waste" is produced by the plant. Describe how the
two Laws of Thermodynamics apply to what you find out in your research. Be thorough. You will
be using the information you gather to engage in a debate with your class about
thermodynamics.

Answers

Answer:

There are four laws of thermodynamics that define fundamental physical quantities (temperature, energy, and entropy) and that characterize thermodynamic systems at thermal equilibrium.

Explanation:

What is one abiotic factor that all biotic factors need to survive??

Answers

Answer:

there r mainly three abiotic factors where all biotic factors need to thrust and survive,

They're i) Air

            ii) Water

           iii) Land

Answer:Water

Explanation:

HELP ME PLZ IT WILL MEAN A LOT

Answers

Answer:

1. B

2.C

Explanation:

I just used logic, it's been a while since I've done this but right now I'm in Honors Chemistry and I think I have the qualifications to answer this question. Sorry if I'm wrong.

What is the molarity of a 750.0 mL aqueous solution that contains 117 g of NaCl?

Answers

Answer:

2.67M

Explanation:

Given: volume of solution = 750.0 mL = 0.750 L Find: molarity

mass of solute = 117 g NaCl

= 58.4428 g/mol (Periodic Table)

Plan: Find the number of moles of solute from the molar mass, then calculate molarity.

Step 1: Find moles of NaCl.

Step 2: Calculate molarity.

Answer: 2.67 M

What time of the year can you see Scorpius

Answers

Answer:

In the northern hemisphere I believe, Scorpius is most visible by looking to the south during July and August around 10:00 PM. The constellation remains visible until mid-September. In the southern hemisphere, Scorpio appears very high in the northern part of the sky until close to the end of September.

Answer:

October 23 to November 21

Explanation:

Not entirely sure what you are asking. . .

If we're talking Scorpius as in:

Scorpius is one of the constellations of the zodiac and is located in the Southern celestial hemisphere. Its name is Latin for scorpion, and its symbol is. (Unicode ♏).

If you discover a new element, how would you know where it should go on the periodic table

Answers

Answer:

the atomic number

Explanation:

it would be in the upper corner

The ions S-2, Cl-1, K+, Ca+2, Sc+3 have the same total number of electrons as the noble gas argon. How would you expect the radii of these ions to vary?

Answers

Answer:

Cl^- <S^2-<Sc^3+ <Ca^2+<K^+

Explanation:

We know that ionic radius of ions decreases from right to left in the periodic table.  This is because, ionic radii decreases with increase in nuclear charge. This explains why; Sc^3+ <Ca^2+<K^+.

Secondly, even though Cl^- is isoelectronic with S^2-, the size of the nuclear charge in Cl^-  is larger compared to that of  S^2- . Hence Cl^-  is smaller than S^2- in ionic radius owing to increased nuclear attraction in Cl^-.

Give answer fast (C)
☹️☹️☹️☹️☹️☹️​

Answers

Plug in the numbers
(-3)^3 + (-3)^2 + -3 + 5
-27 + 9 - 3 + 5
-18 - 3 + 5
= -16
The answer is -16 for C

Question 5 of 10
Two hydrogen atoms combine chemically with one oxygen atom to form
water. What is water?
O A. An atom
B. A molecule
O C. An element
O D. A mixture

Answers

Actually water is a compound since it is a chemical mixture of two elements but since compound is not one of the options you can pick D. a mixture

Define Mole Concept give 3 Significance of Mole concept​

Answers

Answer:

The mole is important because it allows chemist to work with a subatomic world with macro world units and amount. Atoms molecules and formula units are very small and very difficult to work with usually. However the mole allows a chemist to work with amount large enough to use.

In the International System of Units, the mole is the unit of substance quantity. How many elementary entities of a certain substance are present in an item or sample is determined by the quantity of that material.

Three significance of Mole concept​ are:

1) Since atoms and molecules are so tiny, we can count them using the mole idea by weighing extremely little quantities of material.

2) It sets a benchmark for figuring out the stoichiometry of reactions.

(3) It explains the characteristics of gases.

The mole is specified as exactly 6.02214076×10²³ elementary entities.

Learn more about mole, here:

https://brainly.com/question/22540912

#SPJ2

When Jorge looks at the Moon from Earth, he sees different phases of the Moon depending on the time of the month he observes the Moon. Why does the Moon have different phases during the month?

Answers

Answer:

Because of the revolution of the moon about the earth.

Explanation:

The moon is the natural satellite of the earth; which rotates about its axes and orbits around the earth. As the moon orbits the earth with respect to time, it would complete a revolution in 27.3 days.

During revolution, different phases of the moon can be observed by someone on the earth. This is due to its location at different time during the process. Therefore, Jorge was able to see different phases of the moon because of its revolution about the earth.

what type of heat transfer takes place when you come in contact with a snow flake on a cold day?

Answers

Answer:

Conduction

Explanation:

Conduction is how heat transfers through direct contact with objects that are touching. Any time that two objects or substances touch, the hotter object passes heat to the cooler object.

Answer:

Conduction

Explanation:

Conduction is how heat transfers through direct contact with objects that are touching. Any time that two objects or substances touch, the hotter object passes heat to the cooler object.

Metals tend to — electrons and nonmetals tend to —
Electrons

Answers

Answer:

Non-metals tend to gain electrons to attain Noble Gas configurations. The have relatively high Electron affinities and high Ionization energies. Metals tend to lose electrons and non-metals tend to gain electrons, so in reactions involving these two groups, there is electron transfer from the metal to the non-metal.

explain with example the combination and decomposition reaction.​

Answers

Answer:

Decomposition reactions require an input of some form of energy. For example, under the influence of an electric field, water breaks down to give hydrogen and oxygen. In the presence of sunlight, hydrogen peroxide decomposes into oxygen and water.

One of the steps to sweeten sour gas using the Claus process is reacting
hydrogen sulfide gas with sulfur dioxide gas to produce water vapour and sulfur.
16 H2S(g) + 8 SO2(g) → 16 H2O(g) + 3 Sg(s)
8.56 kL of hydrogen sulfide at 175 kPa and 250 °C reacts with excess sulfur
dioxide. Calculate the mass, in kg, of sulfur produced.

Answers

The mass, in kg, of Sulfur produced : 2.072 kg

Further explanation

Given

V = 8.56 kL = 8560 L

P = 175 kPa = 1,73 atm

T = 250 + 273 = 523 K

Required

mass of Sulfur produced

Solution

mol of H₂S :

[tex]\tt n=\dfrac{PV}{RT}\\\\n=\dfrac{1.73\times 8560}{0.082\times 523}\\\\n=345.3[/tex]

mol of Sulfur based on mol  H₂S as a limiting reactant( excess Sulfur  dioxide)

From equation, mol ratio  H₂S : S = 16 : 3, so mol S :

[tex]\tt \dfrac{3}{16}\times 345.3=64.74[/tex]

Mass S(Ar = 32 g/mol) :

= mol x Ar s

= 64.74 x 32

= 2071.68 g = 2.072 kg

What common kitchen appliance uses radiation to heat food ?

Answers

Answer:

microwave

Explanation:

Answer:

Toaster ovens & Microwave

Explanation:

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