Answer:
The noble gases (Group 18) are located in the far right of the periodic table and were previously referred to as the "inert gases" due to the fact that their filled valence shells (octets) make them extremely nonreactive. The noble gases were characterized relatively late compared to other element groups.
The History
The first person to discover the noble gases was Henry Cavendish in the late 180th century. Cavendish distinguished these elements by chemically removing all oxygen and nitrogen from a container of air. The nitrogen was oxidized to NO2 by electric discharges and absorbed by a sodium hydroxide solution. The remaining oxygen was then removed from the mixture with an absorber. The experiment revealed that 1/120 of the gas volume remained un-reacted in the receptacle. The second person to isolate, but not typify, them was William Francis (1855-1925). Francis noted the formation of gas while dissolving uranium minerals in acid.
Argon
In 1894, John William Strutt discovered that chemically-obtained pure nitrogen was less dense than the nitrogen isolated from air samples. From this breakthrough, he concluded that another, unknown gas was present in the air. With the aid of William Ramsay, Strutt managed to replicate and modify Cavendish's experiment to better understand the inert component of air in his original experiment. The researchers' procedure differed from the Cavendish procedure: they removed the oxygen by reacting it with copper, and removed the nitrogen in a reaction with magnesium. The remaining gas was properly characterized and the new element was named "argon," which originates from the Greek word for "inert."
Helium
Helium was first discovered in 1868, manifesting itself in the solar spectrum as a bright yellow line with a wavelength of 587.49 nanometers. This discovery was made by Pierre Jansen. Jansen initially assumed it was a sodium line. However, later studies by Sir William Ramsay (who isolated helium on Earth by treating a variety of rare elements with acids) confirmed that the bright yellow line from his experiment matched up with that in the spectrum of the sun. From this, British physicist William Crookes identified the element as helium.
Neon, Krypton, Xenon
These three noble gases were discovered by Morris W. Travers and Sir William Ramsay in 1898. Ramsay discovered neon by chilling a sample of the air to a liquid phase, warming the liquid, and capturing the gases as they boiled off. Krypton and xenon were also discovered through this process.
Radon
In 1900, while studying the decay chain of radium, Friedrich Earns Dorn discovered the last gas in Group 18: radon. In his experiments, Dorn noticed that radium compounds emanated radioactive gas. This gas was originally named niton after the Latin word for shining, "nitens". In 1923, the International Committee for Chemical Elements and International Union of Pure Applied Chemistry (IUPAC) decided to name the element radon. All isotopes of radon are radioactive. Radon-222 has the longest half-life at less than 4 days, and is an alpha-decay product of Radium-226 (part of the U-238 to Pb-206 radioactive decay chain).
The Electron Configurations for Noble Gases
Helium 1s2
Neon [He] 2s2 2p6
Argon [Ne] 3s2 3p6
Krypton [Ar] 3d10 4s2 4p6
Xenon [Kr] 4d10 5s2 5p6
Radon [Xe] 4f14 5d10 6s2 6p
Explanation:
Use the data in the Successive Ionization Energies and Electron Affinity tables to determine the following. (Assume the values in the Successive Ionization Energies table are given to the ones place.) (a) the electron affinity of Ar2+ kJ/mol (b) the electron affinity of Si + kJ/mol (c) the ionization energy of Cl − kJ/mol (d) the ionization energy of Cl kJ/mol (e) the electron affinity of Cl + kJ/mol
Answer:
Use the data in the Successive Ionization Energies and Electron Affinity tables to determine the following. (Assume the values in the Successive Ionization Energies table are given to the ones place.)
(a)
the electron affinity of Ar2+
kJ/mol
(b)
the electron affinity of S+
kJ/mol
(c)
the ionization energy of Cl−
kJ/mol
(d)
the ionization energy of Cl
kJ/mol
(e)
the electron affinity of Cl+
kJ/mol
Successive Ionization Energies in Kilojoules per Mole for the Elements in Period 3 General increase 13 14 Element 11 12 I. 16
Explanation:
What is the pressure if the height of a column of mercury is 0.20 m and the density of mercury is 13,600 kg/m3? (remember, gravity is 9.81 m/s2)
Answer:
[tex]p=26683.2Pa[/tex]
Explanation:
Hello,
In this case, since the pressure is computed via:
[tex]p=h*\rho*g[/tex]
Whereas h is the 0.520-m height, [tex]\rho[/tex] is the 13600-kg/m³ density and the g the 9.81-m/s² gravity. Thus, the pressure in Pa is:
[tex]p=0.20m*13,600 \frac{kg}{m^3} *9.81\frac{m}{s^2} \\\\p=26683.2\frac{kg*\frac{m}{s^2} }{m^2} =26683.2\frac{N}{m^2}\\ \\p=26683.2Pa[/tex]
Best regards.
Which pair of elements would most likely have a similar arrangement of outer
electrons and have similar chemical behaviors?
boron and aluminum
helium and fluorine
carbon and nitrogen
chlorine and oxygen
Answer:
Boron and Aluminum
Explanation:
If you write the electron configuration for boron and aluminum, you get:
[tex]1s^22s^22p^1[/tex] for boron and [tex]1s^22s^22p^63s^23p^1[/tex] for aluminum. Both have 3 valance electrons and has 2 electrons in a s-orbital and 1 in a p-orbital. These valance electron similarities are based on the column/group the elements are. Therefore, Boron and Aluminum have similar chemical behaviours and similar arrangement of outer/valance electrons.
What is the force of a 10 kg bowling ball with an acceleration of 8 m/s/s?
0 18 N
0 80 N
O 2N
The answer is 80N
(hope this helps you!!!)
Which of these four elements is the most reactive metal?
Answer:
Rubidium
Answer: Rubidium is the most reactive metal. Explanation: Metals are the elements that looses electrons and thus, their chemical reactivity will be the tendency to loose electrons.
Explanation:
describe the changed that happened in the crayon and candle when they cooled after 3 to 5 minutes.
Answer:
The change was physical, meaning it went from liquid to solid, or the other way around.
Explanation:
This is about change in substances.
Physical Change took place.
There are two major changes in chemistry. They are;- Physical changes: These are changes where no new substances are formed but only undergoes change of state.
- Chemical changes: These are changes where new substances are formed.
Now, for crayon and candle to be cooled, it means they were heated.Now when we heat either crayon or candle, we initially see it melting with a liquid like substance flowing down. Thereafter, when cooled, they become solid again.
In all these, no new substance was formed as they just only changed from solid to liquid and back to solid.This is what physical change is all about.
Read more at; brainly.com/question/19046658
Which phrase describes the element carbon-14?
We know that carbon -14 is a radioactive isotope of carbon
It is used in carbon dating to know the age of different forms of dead organism including plants...
So it is used for estimating the age of sedimentry rocks which contains dead debris of plants and animals,
it can be produced from N14 by radioactive reaction of N-14 with neutron.
It is found in organisms
Answer:
Found in organisms remains.
Explanation:
Hope this helped
In which atmospheric layer is the ozone layer?
A.troposphere
B.mesosphere
C.stratosphere
D.thermosphere
Answer:
stratosphere
Explanation:
contains a high concentration of ozone in relation to other parts of the atmosphere, although still small in relation to other gases in the stratosphere.
Answer:
stratosphere
Explanation: Most atmospheric ozone is concentrated in a layer in the stratosphere, about 9 to 18 miles (15 to 30 km) above the Earth's surface. Ozone is a molecule that contains three oxygen atoms.
What was one main point of Dalton’s atomic theory?
A. That atoms were made up of positive and negative charges
B. That atoms changed as they formed compounds
C. That atoms has a nucleus at the center
D. That atoms made up the smallest form of matter
The main point of Dalton’s atomic theory is that the atoms are made up the smallest form of matter. Hence Option (D) is Correct
What is Dalton's Atomic Theory ?
The 5 main points of Dalton's Atomic theory was ;
Elements are composed of extremely small particles called atoms that are indivisible and indestructibleAll atoms of a given element are identical; they have the same size, mass, and chemical propertiesAtoms of 1 element are different from the atoms of all other elementsCompounds are composed of atoms of more than 1 element. The relative number of atoms of each element in a given compound is always the same.Chemical reactions only involve the rearrangement of atoms. Atoms are not created or destroyed during chemical reactions.Therefore, The main point of Dalton’s atomic theory is that the atoms are made up the smallest form of matter. Hence Option (D) is Correct
Learn more about Atom here ;
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Answer:
D is correct
Explanation:
What is the formula for the aqueous salt produced when hydroiodic acid is neutralized by potassium hydroxide?
Answer:
KOH(aq) + HCI(aq) -----> KCI(aq )+ H2O
base acid salt water
hope this helps :)
Explanation:
The formula for the aqueous salt produced when hydroiodic acid is neutralized by potassium hydroxide is KI. The neutralization reaction between hydroiodic acid and potassium hydroxide is given below.
HI(aq) + KOH(aq) → KI(aq) + H2O(l)
What is neutralization reaction?The reaction between acid and base to form salt and water is called neutralization reaction.
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What are two weather factors that are directly influenced by ocean currents
O Air density and humidity
O Air pressure and temperature
O Temperature and humidity
O Precipitation and air pressure
Explanation:
Preciptation and air pressure
Answer:
It is Temperature and humidity. C
Explanation:
I took the test and it said it was C
Four grams of hydrogen react completely with 32 grams of oxygen. Based on the law of conservation of mass how many grams of water will be produced
Se producirán 36 gramos de agua
Explicación: Ya que en una reacción química no puede descubrir ningún cambio en masa total de las sustancias que en ella intervienen, pues en una reacción química ni se gana ni se pierde masa.
A compound is 49 and 6.7 hydrogen and 53 oxygen what’s the empirical formula
Answer:
dangerous woman by ariana grande
Explanation:
Answer:
C6H10O6
Explanation:
Convert % and make them to grams. Convert grams to mols. Use mole ratios to find empirical formula. I will calculate it in a second. Hope this helps for now. This is my quick answer imma check my work one sec.
A student throws a 0.46kg bowling ball at a velocity of 25m/s what is the kinetic energy of the bowling ball in Joules
Answer:
The answer is 143.57 JExplanation:
The kinetic energy of an object can be found by using the formula
[tex]KE = \frac{1}{2} m {v}^{2} \\ [/tex]
where
m is the mass
v is the velocity
From the question we have
[tex]KE = \frac{1}{2} \times 0.46 \times {25}^{2} \\ = 0.23 \times 625[/tex]
We have the final answer as
143.75 JHope this helps you
The last column of the periodic table contains the noble gases, elements that do not easily form chemical bonds. why don’t these gases tend to form chemical bonds?
PLS HELPPP I WILL MARK BRAINLESY
which of the two pure substance consists of different types of Element
Answer:Two Main Types of Pure Substances
Elements and compounds are the two types of pure substances. Examples of common elements include carbon, nitrogen and hydrogen. They consist of one type of atom and cannot break down into something else. Every pure carbon substance, for example, has the same particles in it.
Explanation:I think
A chemical engineer must calculate the maximum safe operating temperature of a high-pressure gas reaction vessel. The vessel is a stainless-steel cylinder that measures 41.0cm wide and 49.2cm high. The maximum safe pressure inside the vessel has been measured to be 3.70MPa. For a certain reaction the vessel may contain up to 2.50kg of dinitrogen difluoride gas.
Required:
Calculate the maximum safe operating temperature the engineer should recommend for this reaction. Write your answer in degrees Celsius. Be sure your answer has the correct number of significant digits.
Answer:
[tex]T=2.78x10^3 \°C[/tex]
Explanation:
Hello,
In this case, considering that the safe temperature may be computed via the ideal gas law as we now the pressure, mass and volume via the dimensions:
[tex]V=\pi r^2 h=\pi *(41.0cm)^2*49.2cm=2.60x10^5cm^3*\frac{1L}{1000cm^3} =260L[/tex]
The pressure in atm is:
[tex]P=3.70MPa*\frac{1x10^6Pa}{1MPa} \frac{1atm}{101325Pa} =36.5atm[/tex]
And the moles considering the mass and molar mass (66 g/mol) of dinitrogen difluoride (N₂F₂):
[tex]n_{N_2F_2}=2.50kg*\frac{1000g}{1kg}*\frac{1mol}{66g} =37.9mol[/tex]
In sich a way, by applying the ideal gas equation, which is not the best assumption but could work as an approximation due to the high temperature, the temperature, with three significant figures, will be:
[tex]T=\frac{PV}{nR}=\frac{36.5Pa*260L}{37.9mol*0.082\frac{atm*L}{mol*K} }\\ \\T=3053.6K-273.15\\\\T=2.78x10^3 \°C[/tex]
Best regards.
Phosphoric acid, which is commonly used as rust inhibitor, food additive and etching agent for dental and orthopedic use, can be synthesized using a two-step thermal process. In the first step, phosphorus and oxygen react to form diphosphorus pentoxide: P4(l)+5O2(g-2 P20s(g) In the second step, diphosphorus pentoxide and water react to form phosphoric acld P20(9)+3 H200 2H,PO40) Write the net chemical equation for the production of phosphoric acid from phosphorus, oxygen and water.
Answer:
P₄(l) + 5 O₂(g) + 6 H₂O(l) ⇒ 4 H₃PO₄(aq)
Explanation:
Phosphoric acid is synthesized using a two-step thermal process.
In the first step, phosphorus and oxygen react to form diphosphorus pentoxide. The corresponding chemical equation is:
P₄(l) + 5 O₂(g) ⇒ 2 P₂O₅(g)
In the second step, diphosphorus pentoxide and water react to form phosphoric acid. The corresponding chemical equation is:
P₂O₅(g) + 3 H₂O(l) ⇒ 2 H₃PO₄(aq)
We can get the net chemical equation by adding the first step, the second step multiplied by 2, and canceling what is repeated on both sides.
P₄(l) + 5 O₂(g) + 2 P₂O₅(g) + 6 H₂O(l) ⇒ 2 P₂O₅(g) + 4 H₃PO₄(aq)
P₄(l) + 5 O₂(g) + 6 H₂O(l) ⇒ 4 H₃PO₄(aq)
Which is the dependent variable in an experiment? 1.what I observe. 2. what I keep the same 3.What I change in the experiment. HELP NOW
Answer:
1.what I observe.
Explanation:
The dependent variable in an experiment is what is being observed in the experimental procedure.
This variable is the one that is closely tied to the effects originating from changing the independent variables.
Independent variables are the ones that cause the observation being studied. The effects produced and then studied are the dependent variables.When solid Fe metal is put into an aqueous solution of SnSO4, solid Sn metal and a solution of FeSO4 result. Write the net ionic equation for the reaction.
Answer:Fe(s) + Sn^2+(aq) ----> Fe^2+(aq) + Sn(s)
Explanation:
The net ionic equation involved is;
Fe(s) + Sn^2+(aq) ----> Fe^2+(aq) + Sn(s)
We must recall that iron is above tin in the electrochemical series. The implication of this is that, iron has a more negative reduction potential compared to tin.
A metal can displace metals below it in the electrochemical series from their aqeous solution. Hence, iron displaces tin from it's solution.
You will need to balance this reaction
Na3PO4 +
CaCl2 → ? NaCl +_ Ca3(PO4)2
Answer:
2Na₃PO₄ + 3CaCl₂ → 6NaCl + Ca₃(PO₄)₂
Explanation:
Chemical equation:
Na₃PO₄ + CaCl₂ → NaCl + Ca₃(PO₄)₂
Balance chemical equation:
2Na₃PO₄ + 3CaCl₂ → 6NaCl + Ca₃(PO₄)₂
First step:
Na₃PO₄ + CaCl₂ → NaCl + Ca₃(PO₄)₂
Left hand side Right hand side
Na = 3 Na =1
P = 1 P = 2
O = 4 O = 8
Ca = 1 Ca = 3
Cl =2 Cl = 1
2nd step:
2Na₃PO₄ + CaCl₂ → NaCl + Ca₃(PO₄)₂
Left hand side Right hand side
Na = 6 Na =1
P = 2 P = 2
O = 8 O = 8
Ca = 1 Ca = 3
Cl =2 Cl = 1
3rd step:
2Na₃PO₄ + 3CaCl₂ → NaCl + Ca₃(PO₄)₂
Left hand side Right hand side
Na = 6 Na =1
P = 2 P = 2
O = 8 O = 8
Ca = 3 Ca = 3
Cl = 6 Cl = 1
3rd step:
2Na₃PO₄ + 3CaCl₂ → 6NaCl + Ca₃(PO₄)₂
Left hand side Right hand side
Na = 6 Na =6
P = 2 P = 2
O = 8 O = 8
Ca = 3 Ca = 3
Cl = 6 Cl = 6
I need help on this. It’s kinda confusing...
Answer: here u go
Explanation:
A. 3.7 x 10^4
B. 4.56 × 10^-8
C. 8.01 × 10^6
Work for A:
Step 1
To find a, take the number and move a decimal place to the right one position.
Original Number: 37,000
New Number: 3.7000
Step 2
Now, to find b, count how many places to the right of the decimal.
New Number: 3 . 7 0 0 0
Decimal Count: 1 2 3 4
There are 4 places to the right of the decimal place.
Step 3
Building upon what we know above, we can now reconstruct the number into scientific notation.
Remember, the notation is: a x 10b
a = 3.7 (Please notice any zeroes on the end have been removed)
b = 4
Now the whole thing:
3.7 x 104
Step 4
Check your work:
104 = 10,000 x 3.7 = 37,000
Work for B:
Step 1
To find a, take the number and move a decimal place to the right one position.
Original Number: 456
New Number: 0.0000000456
Step 2
Now, to find b, count how many places to the right of the decimal.
New Number: 0 . 0 0 0 0 0 0 0 4 5 6
Decimal Count: 1 2 3 4 5 6 7 8 9 10
There are 2 places to the right of the decimal place.
Step 3
Building upon what we know above, we can now reconstruct the number into scientific notation.
Remember, the notation is: a x 10b
a = 4.56
b = 2
Now the whole thing:
4.56 x 102
Step 4
Check your work:
102 = 100 x 4.56 = 456
Work for C:
Step 1
To find a, take the number and move a decimal place to the right one position.
Original Number: 8,010,000
New Number: 8.010000
Step 2
Now, to find b, count how many places to the right of the decimal.
New Number: 8 . 0 1 0 0 0 0
Decimal Count: 1 2 3 4 5 6
There are 6 places to the right of the decimal place.
Step 3
Building upon what we know above, we can now reconstruct the number into scientific notation.
Remember, the notation is: a x 10b
a = 8.01 (Please notice any zeroes on the end have been removed)
b = 6
Now the whole thing:
8.01 x 106
Step 4
Check your work:
106 = 1,000,000 x 8.01 = 8,010,000
Hope this helps!
What is the percent of iron and oxygen in iron(III) oxide?
Answer:
69.94% iron by mass.
Explanation:
A student dissolves of sodium hydroxide in of water in a well-insulated open cup. He that observes the temperature of the water rise from to over the course of minutes. Use this data, and any information you need from the ALEKS Data resource,
NaOH(s) rightarrow Na+(aq) + OH-(aq)
You can make any reasonable assumptions about the physical properties of the solution. Note for advanced students: it's possible the student did not do the experiment carefully, and the values you calculate may not be the same as the known and published values for this reaction.
1. Is this reaction exothermic, endothermic, or neither.
2. If you said the reaction was exothermic or endothermic, calculate the amount of neat that was released or absorbed by the reaction in this case.
3. Calculate the reaction enthalpy AW per mole of NaOH.
Answer:
This question is incomplete
Explanation:
This question is incomplete but the answer to (1) and steps involved in calculating (2) and (3) will be discussed in the attachment
1. The reaction is an exothermic reaction because heat was given off. Exothermic reaction is a reaction in which heat is released from a reaction into the surroundings. And according to the question, the student observed that the temperature of the water increased during the course of the minutes.
If you worked at a job for $9.00/hour, what type of correlation is the number of hours worked and your take-home pay?
Answer:
There are no options to this question, however, it can be answered. The answer is:
POSITIVE CORRELATION
Explanation:
Correlation refers to the relationship between two variables. It shows how related two variables are to one another. Hence, when two variables are correlated, there exists a relationship between them. Correlation can either be positive or negative depending on how related they are.
A positive correlation is that correlation in which the two variables are influenced to go in the same direction. That is, when one variable increases, the other variable increases as well and vice versa. This is the case in this question regarding the correlation between number of hours worked and take-home pay.
As the number of hours worked increases, the take-home pay also increases and vice versa. Hence, it is a type of POSITIVE CORRELATION
HELPP GIVING AWAY 30 POINTS!!!!!
Determine Your family wants to use
renewable energy to heat your home. Which
renewable energy resource is best suited to
your area? Explain your answer.
Answer:
wood
Explanation:
i can take the seds from the trees to row new trees and still use the wood without causing deforestation
as a student,living in the philippines considered to be part of the global south,how are you going to compete and survive challenges of globalization?
Answer:
Natural Selection
Explanation:
What is the density of a liquid with the same mass as in problem d, if it has a volume of 43.2 mL?
(part d: A liquid has a volume of 62.7 mL and a density of 2.59 g/mL. What is its mass?)
Answer:
3.76
Explanation:
You start by finding the mass of part d. Mass= Density times Volume.In this case you would multiply 62.7 and 2.59 which is 162.393 rounded is 162.4. Then density= mass/ volume which is 162.4/ 43.2. density equals 3.76
What types of materials are better at absorbing energy from radiation?
Answer:
Explanation:
Materials are clothes and heavy rope
i need help filling in these 2 blanks i really need answers asap
is there a word bank so i know which words to chose from?
1st blank: command
2nd blank: messages
Explanation:
I am not too sure about the second blank, but to me it makes sense.