This problem provides the molar mass and radius of a metal that has an FCC unit cell and the density is required.
Firstly, we begin with the formula that relates the aforementioned variables and also includes the Avogadro's number and the volume of the unit cell:
[tex]\rho=\frac{Z*M}{V*N_A}[/tex]
Whereas Z stands for the number of atoms in the unit cell, M the molar mass, V the volume and NA the Avogadro's number. Next, since FFC is able to hold 4 atoms and M and NA are given. Next, we calculate the volume of the atom in the unit given the radius in meters:
[tex]V=a^3=(2*1.92x10^-10m*\sqrt{2} )^3=1.60x10^{-28}m^3/atom[/tex]
And finally the required density in g/cm³:
[tex]\rho=\frac{4*241.5g/mol}{1.60x10^{-28}m^3/atom*6.022x10^{23}atom/mol} \\\\\rho=10025739g/m^3=10.03 g/cm^3[/tex]
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https://brainly.com/question/12977980https://brainly.com/question/13110055Doing Labs at home
I’m a junior and I’m staying home for this semester and I have to take chemistry and a lot of my work is Labs but I don’t know how to do them since I don’t have the materials at home to do the labs. Someone please help!!!
Answer:
go get the stuff.
Explanation:
Balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of Ni and H+ in the balanced reaction? Ni2+(aq) + NH4+(aq) → Ni(s) + NO3-(aq)
In this case, the problem is asking for the balance of a redox reaction in acidic media, in which nickel is reduced to a metallic way and nitrogen oxidized to an ionic way.
Thus, according to the given information, it turns out possible for us to balance this equation in acidic solution by firstly setting up the half reactions:
[tex]Ni^{2+}+2e^-\rightarrow Ni^0\\\\N^{3-}H_4^++3H_2O\rightarrow N^{5+}O_3^-+8e^-+10H^+[/tex]
Next, we cross multiply each half-reaction by the other's carried electrons:
[tex]8Ni^{2+}+16e^-\rightarrow 8Ni^0\\\\2N^{3-}H_4^++6H_2O\rightarrow 2N^{5+}O_3^-+16e^-+20H^+[/tex]
Finally, we add them together to obtain:
[tex]8Ni^{2+}+2N^{3-}H_4^++6H_2O\rightarrow 8Ni^0+2N^{5+}O_3^-+20H^+[/tex]
Which can be all simplified by a factor of 2 to obtain:
[tex]4Ni^{2+}+N^{3-}H_4^++3H_2O\rightarrow 4Ni^0+N^{5+}O_3^-+10H^+\\\\4Ni^{2+}(aq)+NH_4^+(aq)+3H_2O(l)\rightarrow 4Ni(s)+NO_3^-(aq)+10H^+(aq)[/tex]
Hence, the coefficients in front of Ni and H⁺ are 4 and 10 respectively.
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https://brainly.com/question/14965625Which spheres include the water cycle? (Select all that apply.)
biosphere
geosphere
hydrosphere
atmosphere
Answer:
A, B, C, D
Explanation:
The water cycle is included in the atmosphere (water vapor in the air), the geosphere (water collection), the hydrosphere (water on earth: lakes, oceans, rivers), and the biosphere (where water interacts with all living things).
In an ecosystem, the water cycle is included in all the spheres that is biosphere,geosphere,hydrosphere and atmosphere.
What is an ecosystem?Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.
Energy enters the system through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.
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PLEASE ANWSER THIS!!
which is the best definition m of pitch?
A: pitch is how high or low a sound is
B: pitch is how loud a sound is
C: pitch is how well a sound travels through a medium
Answer:
A. because there both high pitched voice and low pitched ( girls have sweet, shrill ,high pitched good voice ) where as boys have horase ,low pitched medium voice )
2. Alex pulls on the handle of a claw hammer with a force of 15 N. If
the hammer has a mechanical advantage of 5.2, how much force
is exerted on the nail in the claw?
Answer:
78n
Explanation:
The output force exerted on the nail in the claw is equal to 78 N which has a mechanical advantage of 5.2.
What is the mechanical advantage?The mechanical advantage can be demonstrated as the ratio of the output force to the Input force. The mechanical advantage of any machine can be expressed in the form of the ratio of the forces utilized to do the work.
The ratio of the resistance to the effort is said to be the actual mechanical advantage which will be less. The efficiency of a machine can be evaluated by equating the ratio of the output to its input.
Given, the input force = 15 N
The mechanical advantage of the hammer = 5.2
Mechanical advantage = Output force/ Input force
5.2 = Output/15
Output force = 15 ×5.2 = 78 N
Therefore, the force is exerted on the nail in the claw is equal to 78 N.
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According to the electron configuration, which atom will be the most reactive?
1s^2 2s^2
1s^2 2s^2 2p^6 3s^2
1s^2 2s^2 2p^6 3s^2 3p^6
1s^2 2s^2 2p^6 3s^2 3p^6 4s^2
Answer:
The fourth atom.
Explanation:
Number of valence electrons in each of the four atoms:
First atom: two ([tex]2\, s^{2}[/tex].)Second atom: two ([tex]3\, s^{2}[/tex].)Third atom: eight ([tex]3\, s^{2}\; 3\, p^{6}[/tex].)Fourth atom: two ([tex]4\, s^{2}[/tex].)Without referring to a periodic table, the first, second, and fourth atoms would all belong to the alkali-earth metal elements. The third atom would belong to a noble gas element. (The four choices are beryllium, magnesium, argon, and calcium, respectively.)
Noble gas elements are highly stable. Thus, the third atom (argon) would be the least reactive among all four choices.
On the other hand, alkali-earth metals are reactive since they tend to lose their valence electrons. The reactivity of an alkali-earth atom depends on its ionization energy (the energy required to take a valence electron away from the atom.)
Since these atoms are in the same group, ionization energy would be smaller for atoms with a larger radius. In a given group, atoms with more filled electron shells would have a larger radius.
The first atom has two filled main shells, the second has three, whereas the fourth has four.
Thus, among the three alkali-earth metals in the choices:
[tex]\begin{aligned}&\text{Number of filled electron shells:} \\ & a < b < d\end{aligned}[/tex].
[tex]\begin{aligned}&\text{Atomic radius:} \\ & a < b < d\end{aligned}[/tex].
[tex]\begin{aligned}&\text{Ionization energy:} \\ & a > b > d\end{aligned}[/tex].
[tex]\begin{aligned}&\text{Reactivity:} \\ & a < b < d\end{aligned}[/tex].
The third choice (a noble gas) is the least reactive among the four choices:
[tex]\begin{aligned}&\text{Reactivity:} \\ & c < a < b < d\end{aligned}[/tex].
Overall, the fourth choice would be the most reactive among the four choices.
true or false: When the value of secondary quantum no . (l) =1 , the magnetic quantum no . ( m ) = 3 .
When the value of secondary quantum number (l) = 1, the magnetic quantum number can be from -1 to +1. The answer would be false.
What are Quantum numbers?The angular quantum number (l) can take any integer between 0 and the value of the principal quantum number (n) less by 1.
In other words, l can be from 0 to n-1.
The magnetic quantum number (m), on the other hand, can take any value between -l to +l.
For example, if l = 1, m can be -1,0, and +1.
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A sample of crude sodium iodide was analysed by the following rection.
I- + SO42- → I2 + H2S (unbalanced)
a)Determine the oxidation number for S in SO42-.
b)The above reaction requires a basic medium. Write the balanced chemical equation. [6 marks]
A sample of crude sodium iodide was analyzed by the following balanced reaction. The oxidation number of S in SO₄²⁻ is +6.
8 I⁻ + 6 H₂O + SO₄²⁻ → 4 I₂ + H₂S + 10 OH⁻
Let's consider the following unbalanced redox reaction.
I⁻ + SO₄²⁻ → I₂ + H₂S
The oxidation number of I goes from -1 (I⁻) to 0 (I₂) so it is oxidized.The oxidation number of S goes from +6 (SO₄²⁻) to -2 (H₂S) so it is reduced.The corresponding half-reactions are:
I⁻ → I₂
SO₄²⁻ → H₂S
We will perform the mass balance adding OH⁻ and H₂O where appropriate.
2 I⁻ → I₂
6 H₂O + SO₄²⁻ → H₂S + 10 OH⁻
Then, we will perform the charge balance adding electrons where appropriate.
2 I⁻ → I₂ + 2 e⁻
8 e⁻ + 6 H₂O + SO₄²⁻ → H₂S + 10 OH⁻
Finally, we will multiply the first half-reaction by 4 and the second by 1, and add them.
4 × (2 I⁻ → I₂ + 2 e⁻)
1 × (8 e⁻ + 6 H₂O + SO₄²⁻ → H₂S + 10 OH⁻)
------------------------------------------------------------
8 I⁻ + 6 H₂O + SO₄²⁻ → 4 I₂ + H₂S + 10 OH⁻
A sample of crude sodium iodide was analyzed by the following balanced reaction. The oxidation number of S in SO₄²⁻ is +6.
8 I⁻ + 6 H₂O + SO₄²⁻ → 4 I₂ + H₂S + 10 OH⁻
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What is the density of a sponge that has a mass of 100g and a volume of 10 mL?
Answer:
10
Explanation:
Equation: d = m/v
100/10 = 10
Calculate the moles of HCl in 15 mL of a 0.50 M solution.
Explanation:
[tex]\tiny\implies Molarity = \dfrac{no. \: of \: moles \: of \: solute \times 1000}{volume \: of \: the \: solution \: (in \: ml)} [/tex]
[tex]\tiny\implies 0.50 = \dfrac{no. \: of \: moles \: of \: solute \times 1000}{15}[/tex]
[tex]\tiny\implies no. \: of \: moles \: of \: solute \times 1000 = 0.50 \times 15[/tex]
[tex]\tiny\implies no. \: of \: moles \: of \: solute \times 1000 = 7.5[/tex]
[tex]\tiny\implies no. \: of \: moles \: of \: solute = \dfrac{7.5}{1000} [/tex]
[tex]\tiny\implies \bf no. \: of \: moles \: of \: solute = 0.075 \: mol[/tex]
Physical change does not produce a nee substance true or false
Answer:
ooooooooh .,.,.,.,.,.,
Answer:
True
TruePhysical change – A change in the size, shape, color, or state of matter of a substance. No new substance is produced.
pls help
A 4.0 L sample of gas has a pressure of 300 kPa at 250K. What will the volume be if the pressure is increased to 500 kPa and the temperature is decreased to 200 K?
Answer:A versatile Ideal Gas Laws calculator with which you can calculate the pressure, volume, quantity (moles) or temperature of an ideal gas, given the other three. Free online gas law calculator a.k.a. PV = nRT calculator which accepts different input metric units such as temperature in celsius, fahrenheit, kelvin; pressure in pascals, bars, atmospheres; volume in both metric and imperial units ...
Which sentence best describes what happens during a change of state from
a solid to a liquid?
A. The temperature stays the same and the particle speed increases.
B. The temperature stays the same and the particle speed stays
constant
C. The temperature increases and the particle speed stays constant.
D. The temperature decreases and the particle speed decreases.
SUBMIT
Answer:
B
Explanation:
as temperature rises, the particles gain kinetic energy (they will move faster) so if temperatures stays constant, so will the movement or vibration of the particles
pls help me right now
Answer:
LETTER
1. D. PURE SUBSTANCES CAN BE FURTHER BROKEN DOWN INTO SIMPLER SUBSTANCES.
2.A
PO PLEASE MARK A BRAINLIESTS ANG MARK A 5 STAR ANG HEART PO PLEASW
The process of returning mines to their original state is called ________________________.
Answer:
Mine Reclamation.Explanation:
The process of returning mines to their original state is called Mine Reclamation. HOPE THIS HELPS :)Pleeeeasee someone who’s good at chemistry?! 10 grade
ASAP
I’ll give points, just help please
Answer:
where is the question????????????
