Answer:
Heat Flux = - 22.5 W/m²
Explanation:
We can use Fourier's Law of Heat Conduction:
q = -kAΔT/t
q/A = -KΔT/t
where,
q/A = Heat Flux = ?
K = Thermal Conductivity = 0.3 W/m.K
ΔT = Change in Temperature = 20°C - 5°C = 15K
t = Thickness = 0.2 m
Therefore,
Heat Flux = -(0.3 W/m.k)(15 k)/(0.2 m)
Heat Flux = - 22.5 W/m²
Negative sign shows the heat flowing out of the system.
Which element is classified as a noble gas?
Oz Ō
Xe
Answer:
Group 8A (or VIIIA) of the periodic table are the noble gases or inert gases: helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). The name comes from the fact that these elements are virtually unreactive towards other elements or compounds.
Explanation:
its XE
what does it mean atoms form chemical bonds to become happy. what does happy really mean
Answer:
so if an atom needs and electron it will form a bond with another so it will balance out.
Explanation:
1.
(02.01 LC)
Modern atomic theory states that atoms are neutral. How is this neutrality achieved? (3 points)
Equal number of neutrons and protons
More electrons than protons
Equal number of protons and electrons
More neutrons than electrons
Explain why the elements Cobalt and Nickel in the fourth period violate the original periodic law as stated by Mendeleev.
Answer:
Explanation:
Dmitri Mendeleev was a Russian scientist that proposed the first periodic table of elements. Elements in his periodic table were arranged according to there relative atomic mass; however cobalt (Co) with an atomic mass of 58.93 was placed before nickel (Ni) with an atomic mass of 58.69 which was an anomaly as according to his law, nickel should come before cobalt since nickel has a lesser mass compared to cobalt.
An atom has the electron configuration shown below. How many valence electrons are in this atom?
Captionless Image
2
3
4
6
What charge would you expect on an ion of this fictitious atom?
Captionless Image
+3, cation
+5, cation
-5, anion
-3, anion
Which occurrence explains why noble gases are essentially unreactive?
Dipole Interactions
VSEPR Theory
Dispersion Forces
Octet Rule
A covalent bond occurs when ________ are shared between two atoms.
electrons
protons
neutrons
dipoles.
A substance conducts electricity well and has a boiling point of 1478 °C. Is this likely an ionic or covalent substance?
Not enough information to answer.
ionic
covalent
Select all the compounds listed below that are covalent compounds.
B
C
D
A
Captionless Image
A
B
C
D
Captionless Image
Trihocus Dipocus
Dihocus Tripocus
Hocus (II) Pocus
Hocus (III) Pocus
Two nonmetal Halloween elements react to form the compound TriTrick DiTreat. What is the formula? Trick = X and Treat = Y
C
D
B
A
Write the formula for Candycorn Pumpkinate. Candycorn (Cc) has a charge of +3 and pumpkinate (PkO) a charge of -2.
A
B
C
D
Which statement best describes the atomic structure of metals?
Valence electrons packed in a lattice arrangement around cations.
Valence electrons packed in a lattice arrangement around anions.
Closely packed cations with loosely held valence electrons.
Loosely packed cations with tightly held valence electrons.
Which of the following properties is NOT explained by metallic bonding?
Crystalline structures
Malleabilty
Ductility
Thermal conductivity
What is the ionic charge of element X in the compound XP? Phosphorus is in group 15 on the periodic table.
1+
1-
3+
3-
_____________is not reactive with only 2 electrons in its valence shell.
Krypton
Helium
Neon
Xenon
How many electrons are shared in the double bonds in the structural formula shown below?
Captionless Image
2
4
6
8
Option 5
How many lone PAIRS are shown in the molecule below?
Captionless Image
none
2
4
8
A molecule of XY (2 nonmetals) is polar because
X is a metal so exhibits magnetic properties.
X and Y are both ions.
it is ionic and all ionic bonds are polar.
the X atom is able to attract the shared electrons more strongly than a Y atom.
Answer:
question no 4 answer is electrons
a cylinder has a mass of 14.98g and a volume of 2.10 ml. what is the cylinder's density?
Answer:
7.133 g/cm^3
Explanation:
Density = mass ÷ volume
Given,
mass = 14.98 g
Volume = 2.10 ml = 2.10cm^3 [because 1 ml= 1cm^3]
density = 14.98÷ 2.10
density = 7.133 g/cm^3
Answer:
[tex]\boxed {\tt d\approx7.13 \ g/mL}[/tex]
Explanation:
The density of an object can be found by dividing the mass by the volume.
[tex]d=\frac{m}{v}[/tex]
The mass of the cylinder is 14.98 grams.
The volume of the cylinder is 2.10 milliliters.
[tex]m=14.98 \ g\\v= 2.10 \ mL[/tex]
Substitute the values into the formula.
[tex]d=\frac{14.98 \ g}{2.10 \ mL}[/tex]
Divide.
[tex]d=7.13333333 \ g/mL[/tex]
Round to the nearest hundredth. The 3 in the thousandth place tells us to leave the 3 in the hundredth place.
[tex]d\approx 7.13 \ g/mL[/tex]
The density of the cylinder is about 7.13 grams per milliliter.
I want to know how I do excess reactant and limiting reactant. Image provided below.
Answer:
Limiting Reactant is going to be NaOH or HCl with given lowest moles. Excess will be the ones with more.
Explanation:
Excess and Limiting reactants are based on the amount you could make in an ideal reaction. M (molarity) is the concentration of the given solutions where moles in the amount (the important part) you have of each. If you only have 0.0100 mol NaOH while you have 0.0400 mol HCl the most a reaction has the potential to use is that 0.0100 mol NaOH, thus making it the limiting reactant as it is limiting the possible amount made. The excess here is 0.0300 mol HCl.
Which component is missing from the process of cellular respiration? Glucose + Oxygen → Carbon Dioxide + ________ + Energy (4 points) a Water b Sugar c Oxygen d Carbon
Answer: Oxygen or carbon I’ll say oxygen
Explanation:
For the reaction CzHg + 50, 3CO2 + 4H20, how many moles of carbon dioxide will be produced for each mole of propane (C3Hg) reacted?
O 3
04
05
HELP ME
A man is walking in the park at night when he sees a shadow suddenly dart across his path. Which glands will be responsible for controlling his “fight or flight” reaction? Check all that apply.
adrenal
thymus
pancreas
hypothalamus
Answer:
Adrenal and Hypothalamus!
Explanation:
Hope this helps!
Answer:
A man is walking in the park at night when he sees a shadow suddenly dart across his path. Which glands will be responsible for controlling his “fight or flight” reaction? Check all that apply.
Adrenal and Hypothalamus
A woman goes to the doctor for blood tests because she has not been feeling well. Tests show that the sugar levels in her blood are too high. In which gland does she most likely have a problem?
Pancreas
Explanation:
As the puck falls, its potential energy (PE):
increases
decreases
stays the same
not enough information?”
Answer:
stay the same
Explanation:
in 3 minutes, one half of an original sample of polonium will decay. What happens to the other half?
Juan noticed that a door that sticks on hot days does not stick when it cools off at night. This is because the metal contracts as it cools. The reason for this is that, as the metal cools, the atoms:
become smaller and take up less space .
slow down and move closer together.
merge together to form fewer atoms.
speed up and move further apart.
A certain electromagnetic radiation has a wavelength of 5.4x10-7m. What is the frequency of this
electromagnetic radiation?
O 1.8 x 10-65-1
O 5.6 x 1014 5-1
O 1.6 x 1011 51
O 1.8 x 10-155-1
O 5.6 x 10551
Answer:
5.6 x 10¹⁴m
Explanation:
Given parameters:
Wavelength = 5.4 x 10⁻⁷m
Unknown:
Frequency of the electromagnetic radiation = ?
Solution:
The speed of all electromagnetic radiation is given as 3.0 x 10⁸m/s
So;
Speed = frequency x wavelength
Wavelength = [tex]\frac{speed}{frequency}[/tex]
Insert the parameters and solve;
Wavelength = [tex]\frac{3 x 10^{8} }{5.4 x 10^{-7} }[/tex]
Wavelength = [tex]\frac{3}{5.4}[/tex] x 10⁸⁻⁽⁻⁷⁾
Wavelength = 5.6 x 10⁻¹ x 10¹⁵
Wavelength = 5.6 x 10¹⁴m
Why is it nearly impossible to compress a liquid?
O A. The particles don't have enough energy to move out of their fixed
positions.
B. The particles have so much energy they move independently of
one another.
C. The particles are close together and can only slide past one
another.
D. The particles are spread so far apart that they do not affect one
another.
A container of N2O3(g) has a pressure of 0.575 atm. When the absolute temperature of the N2O3(g) is tripled, the gas completely decomposes, producing NO2(g) and NO(g). Calculate the final pressure of the gas mixture, assuming that the container volume does not change.
A piston is holding 125 mL of gases at a temperature of 300 K and a pressure of 2.39 atm. What is the volume of the gases if the temperature is increased to 500K and the pressure falls to 2.15 atm
Answer:
231.59 mL
Explanation:
From the question given above, the following data were obtained:
Initial volume (V₁) = 125 mL
Initial temperature (T₁) = 300 k
Initial pressure (P₁) = 2.39 atm
Final temperature (T₂) = 500 k
Final pressure (P₂) = 2.15 atm
Final volume (V₂) =..?
The new volume of the gas (V₂) can be obtained by using the combined gas equation as shown below:
P₁V₁ /T₁ = P₂V₂ /T₂
2.39 × 125 /300 = 2.15 × V₂ /500
Cross multiply
300 × 2.15 × V₂ = 2.39 × 125 × 500
645 × V₂ = 149375
Divide both side by 645
V₂ = 149375/645
V₂ = 231.59 mL
Therefore, the new volume of the gas is 231.59 mL
The electronegativity of manganese is 1.6, sulfur is 2.5, oxygen is 3.5, chlorine is 3.0, and bromine is 2.8. With which element will manganese
react to form ionic compounds?
A. sulfur
B. oxygen
C. chlorine
D. bromine
1 Sound waves, water waves, and light waves are all alike in that they all ____________.
Answer:
They all produce a type of energy
Explanation:not sure but in wat i remenber that wat i learned in 5th grade
3. Unscramble the name of internal organs nesintites
Answer:
intestines?
Explanation:
apparently my answer needs to be 20 words long so I'ma write all this so i can answer
C. Use Hess's law and the following equations to calculate ΔH for the reaction N2(g) + 2O2(g) N2O4(g). (Show your work.) (8 points)
2NO2(g) N2O4(g) ΔH = –57.0 kJ/mol
N2(g) + O2(g) 2NO(g) ΔH = 180.6 kJ/mol
2NO2(g) 2NO(g) + O2(g) ΔH = 114.4 kJ/mol
PLS HELP I NEED THIS RIGHT NOW!!
THANKS!!
50 points for whoever give me an answer!!
Answer:
ΔH=9.2 KJ
Explanation:
2NO₂→N₂O₄ ΔH=-57 KJ/mol
N₂ + O₂→2NO ΔH=180.6 KJ/mol
2NO + O₂→2NO₂ ΔH= -114.4 (notice this was reversed and sign changed
_____________________________________________
N₂+2O₂→N₂O₄ ΔH= 9.2 KJ
By reversing the third equation, we can get the O₂ on the left side or the (reactant side) so that we can get a total of 2O₂ in the final equation on the bottom. Cross out 2NO₂ on the first equation on the reactant side and 2NO₂ in equation 2 on the product side. You also want to cross out 2NO in the third equation on both the reactant and product side. This leaves the same above the line as below the line.
Since you reverse equation 3, the change in enthalpy will change sign so you input -57, 180.6 and -114.4 to get 9.2 KJ
Hope that helps.
Is electrons positive or negative?
Answer:
Negative
Explanation:
Because i learned it in 5th grade
Answer:
negative
Explanation:
When you are missing an electron or two, you have a positive charge. When you have an extra electron or two, you have a negative charge.
A recently reported mutase may generate an intermediate having a free radical. If you studied this reaction, what evidence would you look for in the mechanism that would be characteristic of other mutase reactions?
Answer:
homolytic cleavage of a covalent bond.
Explanation:
Homolytic cleavage: In chemistry, the term "homolytic cleavage" is described as a process that involves breaking of a particular covalent bond in a way that every fragment tends to get "one" shared electrons and it often produces or gives rise to free radicals. It is also referred to as "homolysis" or "homolytic bond cleavage".
In the question above, the given statement represents "homolytic cleavage of a covalent bond".
Which of the following indicates the most basic solution?A. [H+] = 1 × 10-10 MB. pOH = 6.7C. [OH-] = 7 × 10-5 MD. pH = 4.2
Answer:
The most basic solution is A
Explanation:
In order to solve the problem, we can compare the pH of the solutions. The most basic solution is the one with the highest pH.
A. [H⁺] = 1 × 10⁻¹⁰ M
pH = - log [H⁺] = - log (1 × 10⁻¹⁰) = 10
B. pOH = 6.7
pH = 14 - pOH = 14 - 6.7 = 7.3
C. [OH⁻] = 7 × 10⁻⁵ M
pOH = - log [OH⁻] = -log (7 × 10⁻⁵) = 4.15
pH = 14 - pOH = 14 - 4.15 = 9.8
D. pH = 4.2
According to this, solution A has the highest pH (pH=10), thus this is the most basic solution.
A sample of Ar gas has a pressure of 1.20 atm at 125°C and a volume of 1.00 L. What would the temperature be (°C) with a pressure of 1.80 atm and constant volume?
Answer:
597K
Explanation:
Given parameters:
Initial pressure = 1.2atm
Initial temperature = 125°C = 125 + 273 = 398K
Initial volume = 1.00L
Final pressure = 1.80atm
Final volume = 1.00L
Unknown:
Final temperature = ?
Solution:
To solve this problem, we must understand that at constant volume, the pressure of a given mass of gas varies directly with the absolute temperature.
Mathematically;
[tex]\frac{P_{1} }{T_{1} }[/tex] = [tex]\frac{P_{2} }{T_{2} }[/tex]
where P and T are the pressures
1 and 2 are the initial and final states
Now insert the parameters and solve;
[tex]\frac{1.2}{398}[/tex] = [tex]\frac{1.8}{T_{2} }[/tex]
T₂ x 1.2 = 398 x 1.8
T₂ = 597K
A 0.25g sample of Lead-210 has a half life of 20.4 years. Will all of the Lead undergo radioactive decay in 150 years? Explain.
(I really need help on this this the last question for my assignment but i’m completely lost since i don’t think she covered how we’re supposed to solve this and explain it)
Answer:
Using the equation A(t) = 400e-.032t
a) replace t with 4 so A(4) = 400e((-.032)(4))
The hardest part about this is making sure to use order of operations. Be certain it works like this:
A(4) = 400e-.128
A(4) = 400(.8799)
A(4) = 351.9 grams
b) A(8) = 400e((-.032)(8)) = 309.7 grams
c) A(20) = 400e((-.032)(20)) = 210.9 grams
Note here that even after 20 years, not quite half of the original amount is gone. So, we can anticipate that in finding the half life, that our answer should be slightly greater than 20 years.
d) 200 = 400e(-.032t)
Divide both sides of the equation by 400.
.5 = e(-.032t)
Change this to logarithmic form.
Ln .5 = -.032t
-.6931≈ -.032t
t ≈ 21.7 years
Explanation:
Easy Points
Given the electron configuration: 1s22s22p63s23p64s23d104p65s24d4
Select the correct element
A. Mo
B.Cr
C. Y
D.Sc
Answer:
A. Mo
Explanation:
The given electron configuration: 1s22s22p63s23p64s23d104p65s24d4 shows 42 electrons and Molybdenum has atomic number 42.
But the correct electronic configuration of molybdenum is [Kr]4d5 5s1, and not [Kr]5s24d4 which is based on the diagonal rule.
The diagonal rule states that a half full 5s subshell and half-full 4d subshell are more stable than a full 5s subshell and 4d filled with four electrons.
Hence, the correct element is "A. Mo".
How many gold atoms are present in 4.0 x 10-10 mol of gold?
Answer:
2.408 x 10^14
Explanation:
Write the formula for each compound that contains a polyatomic ion. potassium bicarbonate: aluminum phosphate: copper(II) hydroxide:
Explanation:
A polyatomic ion refers to an ion that contains more than one atom.
Potassium Bicarbonate contains the Potassium ion and bicarbonate ion.
The formula is given as; KHCO₃
Aluminium Phosphate contains the Aluminium ion and Phosphate ion.
The formula is given as; AlPO4
Copper(II)hydroxide contains copper ion and hydroxide ion.
The formula is given as; Cu(OH)₂
A solution contains 1.694 mg CoSO4 (155.0 g/mol) per milliliter. Calculate (a) the volume of 0.08640 M EDTA needed to titrate a 25.00-mL aliquot of this solution. (b) the volume of 0.009450 M Zn2 needed to titrate the excess reagent after addition of 50.00 mL of 0.08640 M EDTA to a 25.00-mL aliquot of this solution.
Answer:
the answer is in the screenshot
Explanation:
hope this helps
Moles of any substance is given by the molar mass and the mass. The volume of EDTA required to titrate is 3.16 mL and the volume of zinc required to titrate is 22.8 mL.
What is molarity?Molarity is the property of the solution that gives the concentration of the solute present in the solution.
Given,
Mass of cobalt sulfate = 1.697 gm
The molar mass of cobalt sulfate = 155 g/mol
In the first part, the volume of the aliquot is 25 mL and the molarity is 0.08640 M.
The reaction is shown as:
Co²⁺ + H₄Y → CoH₂Y + 2H⁺
Moles of cobalt: n = 0.001694 ÷ 155 = 0.0000109 moles
In 25 ml aliquot moles of cobalt are, 0.000273 moles.
The volume of EDTA solution is calculated as:
V = moles ÷ Molarity
= 0.000273 mole ÷ 0.0864 mol/ L
= 3.16 mL
Hence, 3.16 mL of EDTA is required.
For the second part, moles of EDTA are calculated as:
n = 0.008640 × 0.050 = 4.32 ×10⁻⁴
In a 25 mL, sample moles of EDTA are 2.16 × 10⁻⁴ moles.
Excess moles of EDTA in the solution:
0.000432 - 0.000216 = 0.000216 moles
The volume of EDTA is calculated as:
V = 0.000216 ÷ 0.009450
= 0.0228 L
Hence, 22.8 mL of zinc is required.
Learn more about molarity here:
https://brainly.com/question/22714469
#SPJ2