Within a period, the atom size decreases with increasing group number (from left to right), since the nuclear charge and the number of external electrons increase within the period, but the number of shells does not. The electrons are more strongly attracted to the nucleus and are therefore closer to the nucleus.
6. A student is using colored beads to make a model of aluminum sulfate, Al2(SO4)3. Aluminum atoms are represented by blue beads, sulfur atoms by yellow beads, and oxygen atoms by green beads. What combination of beads should the student use for the model? F. 6 blue, 3 yellow, and 7 green G. 2 blue, 1 yellow, and 4 green H. 2 blue, 3 yellow, and 12 green J. 6 blue, 12 yellow, and 12 green
Answer:
H. 2 blue, 3 yellow, and 12 green
Explanation:
Aluminium atoms (Al) = Blue Beads
Oxygen Atoms (O) = Green Beads
Sulfur (S) = Yellow beads
From the compound Al2(SO4)3, the number of atoms present are;
Al = 2
S = 3
O = 12
This means the model would contain;
2 Blue beads
12 Green beads
3 Yellow beads
The correct option is; H. 2 blue, 3 yellow, and 12 green
Answer:
H
Explanation:
Al(blue):2
S(yellow):3
O(green):4*3=12
so 2 blue beads 3 yellow beads and 12 green beads don't time the 2*3 it's not the same compound
good luck!!!
A certain drug has a half-life in the body of 4.0h. What should the interval between doses be, if the concentration of drug in the body should not fall below 15.% of its initial concentration? Round your answer to 2 significant digits.
Answer:
Explanation:
half life = 4 h
initial concentration = 100
final concentration = 15
Time = t
No of half life x = t / 4
15 = 100 x ( 1/2 )ˣ
.15 = ( 1/2 )ˣ
ln .15 = - x ln2
x = - ln .15 / ln 2
= 1.897 / .693
x = 2.737
x = t / 4
t = 2.737 x 4 = 11 h approx .
Explain why we would only ever see a full moon at night
Answer:
The moon is only visible during part of each month. ... When the moon is opposite the sun in the sky (which is when full moon happens), it will rise as the sun sets and set as the sun rises. Therefore, a full moon will be up all night long, but not during the day.
Explanation:
During full moon, the sun and moon will be in opposite sides. The illuminated portions of moon can be seen only in night in earth.
What is full moon ?Full moon appears once in a every lunar cycle. That is the full part of moon is visible at this time. After the first two quarters, moon passes to waxing gibbous state, and then turns to full moon.
The moon's lit side faces earth's night side at the time of the full moon, when the sun and moon are on opposite sides of the planet. Therefore, a full moon is only visible at night.
It is quite possible that you saw a full moon at least one day before or after the real full moon phase if you have ever seen one shortly after dawn or just before sunset.
Rarely, under ideal circumstances, you could even be able to view a real full moon rising or setting opposite the sun, quite near the horizon. However, the moon typically never rises over the horizon.
Find more on full moon:
https://brainly.com/question/15024267
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Photosynthesis
Definition in youre own words? thank you<3
Answer:
the process of plants taking the sunlight and turning it into food for the plant.
Explanation:
Samantha was not feeling well. She had a fever and felt nauseous. Her mother took Samantha to the doctor who prescribed an antibiotic. What kind of infectious agent did Samantha have?
Group of answer choices
A)Parasitic
B)Fungal
C)Viral
D)Bacterial
Answer:
D
Explanation:
i did it before
What is the relationship between gravity and the size of an object?
the bigger the object the more weight of the planet or gravity is acted upon if
does chlorine or silicone have a smaller atomic radius and why
Answer: Chlorine.
Explanation:
Since chlorine's 17 protons are greater than magnesium's 12 protons, chlorine will have a greater effective nuclear charge to draw chlorine's valence electrons closer to the nucleus and, thus, chlorine is expected to have the smaller atomic radius, while magnesium with the lower effective nuclear charge is expected to have a smaller amount of radius.
What is the rule of Conservation of Mass?
Answer: It is the principle that matter cannot be created or destroyed.
Explanation:
Substance B is hard, does not conduct electricity, and melts at 1200 °C. Substance B is likely a(n):
(a) ionic solid
(b) metallic solid
(c) molecular solid
(d) covalent network solid
What specific portion of the gill is used to increase surface area though which gas (oxygen and carbon dioxide) exchange take place?
Answer:
gill lamellae
Explanation:
Gills in fishes are structures that permit fish to carry out gaseous exchange in water. Fishes exchange gases such as oxygen and carbon dioxide using gills.
Fish gills carry out their activity mainly through its major component called the gill lamellae. These are comb-like filaments which help increase the surface area of the gills in order to facilitate gaseous exchange
What is the molarity of a HNO3 solution prepared by adding 290.7 mL of water to 350.0 mL of 12.3 M HNO3?
Answer:
6.72M of HNO3
Explanation:
In the problem you are diluting the original HNO3 solution by the addition of some water. The final volume is:
290.7mL + 350.0mL = 640.7mL
And you are diluting the solution:
640.7mL / 350.0mL = 1.8306 times
As the original concentration was 12.3M, the final concentration will be:
12.3M / 1.8306 =
6.72M of HNO3Alkali metals, such as potassium, must be transported in special sealed containers because they have the ability to burn or explode upon contact with water due to their high reactivity. This is an example of a __________.
Answer:
The Group 1 elements in the periodic table are known as the alkali metals. They include lithium, sodium and potassium, which all react vigorously with water to produce an alkaline solution.
Explanation:
2 2 6 2 6 2 10 3
1s 2s 2p 3s 3p 4s 3d 4p
=
Answer:
ARSENIC
Explanation:
It has an atomic number of 33
conditions under which metals react with water
Answer:
Reactions of Metals with Water
Metals with moderate to low reactivity react very slowly with water. However, they react moderately with steam when heated and give hydrogen gas and metal oxides. Metals low in the metal reactivity series do not react with water even at high temperature.
Explanation:
Order of reactivity Metal Reactions with water or steam
↑ sodium (Na) Vigorous reaction with cold water
↓ calcium (Ca) Less vigorous reaction with cold water
least reactive magnesium (Mg) Slow reaction with cold water, vigorous . with hot water
what is the frequency of light emitted when the electron in a hydrogen atom undergoes a transition from energy level n
Complete question is;
What is the frequency of light emitted when the electron in a hydrogen atom undergoes a transition from energy level n=6 to level n=3?
Answer:
Frequency = 2.742 × 10^(14) s^(-1)
Explanation:
First of all, the energy of hydrogen electron from online values is;
E_n = -2.18 × 10^(-18) × (1/n²) J
n is the principal quantum number
We are told that hydrogen atom undergoes a transition from energy levels n = 3 to n = 6.
Thus, it means we have to find the difference between the electrons energy in the energy levels n = 3 to n = 6.
Thus;
E_n = E_6 - E_3
Thus;
E_n = [-2.18 × 10^(-18) × (1/6²)] - [-2.18 × 10^(-18) × (1/3²)]
E_n = (2.18 × 10^(-18)) × [-1/36 + 1/9]
E_n = 0.1817 × 10^(-18) J
From Planck expression, we can find the frequency. Thus;
E = hf
Where h is Planck's constant = 6.626 × 10^(-34) m²kg/s
Thus;
0.1817 × 10^(-18) = 6.626 × 10^(-34) × f
f = (0.1817 × 10^(-18))/(6.626 × 10^(-34))
f = 2.742 × 10^(14) s^(-1)
What is the most highly populated rotational level of Cl2 (i) 25deg C and (ii) 100 deg C? Take B=0.244cm-1.This question should not be resubmitted, it is a textbook question from the Atkins physical chemistry txtbook. 10 e.
Answer:
i
[tex]J_{m} = 20 [/tex]
ii
[tex]J_{m} = 22.5 [/tex]
Explanation:
From the question we are told that
The first temperatures is [tex]T_1 = 25^oC = 25 +273 =298 \ K[/tex]
The second temperature is [tex]T_2 = 100^oC = 100 +273 = 373 \ K[/tex]
Generally the equation for the most highly populated rotational energy level is mathematically represented as
[tex]J_{m} = [ \frac{RT}{2B}] ^{\frac{1}{2} } - \frac{1}{2}[/tex]
Here R is the gas constant with value [tex]R =8.314 \ J\cdot K^{-1} \cdot mol^{-1}[/tex]
Also
B is given as [tex]B=\ 0.244 \ cm^{-1}[/tex]
Generally the energy require per mole to move 1 cm is 12 J /mole
So [tex]0.244 \ cm^{-1}[/tex] will require x J/mole
[tex]x = 0.244 * 12[/tex]
=> [tex]x = 2.928 \ J/mol [/tex]
So at the first temperature
[tex]J_{m} = [ \frac{8.314 * 298 }{2* 2.928 }] ^{\frac{1}{2} } - 0.5 [/tex]
=> [tex]J_{m} = 20 [/tex]
So at the second temperature
[tex]J_{m} = [ \frac{8.314 * 373 }{2* 2.928 }] ^{\frac{1}{2} } - 0.5 [/tex]
=> [tex]J_{m} = 22.5 [/tex]
SOMEONE PLEASE HELP I WILL GIVE BRAINLIEST PLEASEEEEE!!!!!!!!!!
MY ELEMENT IS NICKEL!!
Answer:
Metallurgy can be isolate other elements. Iron and bronze are the common metalsNickel is the metal which reacts with many metalsSome halogen and discredited metalsA gaseous compound Y contains carbon and hydrogen only and has a density
of 1.696 g dm-3 at 95.3 kPa pressure and 298K. Assume that Y behaves ideally,
calculate its molar mass and deduce its molecular formula. Given 1kPa =1 x 103Nm-2
.
Answer:
[tex]M=44.06\frac{g}{mol}[/tex]
Explanation:
Hello.
In this case, knowing the temperature, density and temperature of Y which behaves ideally, we can write the ideal gas equation:
[tex]PV=nRT[/tex]
Whereas the moles are equal to the mass over the molar mass of Y:
[tex]PV=\frac{m}{M} RT[/tex]
Thus, solving for the molar mass we write:
[tex]M=\frac{mRT}{PV}[/tex]
Yet, since density is mass of over volume, we then write:
[tex]M=\frac{\rho RT}{P}[/tex]
Considering the pressure in atm and the density in g/L:
[tex]P=95.3kPa*\frac{1atm}{101.325kPa}=0.941atm\\\\\rho=1.696\frac{g}{dm^3} *\frac{1dm^3}{1L}=1.696\frac{g}{L}[/tex]
Therefore, by plugging the values in, we obtain:
[tex]M=\frac{1.696\frac{g}{L} *0.082\frac{atm*L}{mol*K}*298K}{0.941atm}\\\\M=44.06\frac{g}{mol}[/tex]
Thus, the gas may be propane ([tex]C_3H_8[/tex]) since it molar mass is 44.11 g/mol.
Best regards!
Determine the mass of hydrogen gas if 36 grams of water undergoes electrolysis to produce hydrogen and oxygen.
Answer:
2.01 g H₂
Explanation:
The chemical equation for the electrolysis of water is
2 H₂O ⇒ 2 H₂ + O₂
Convert grams of water to moles. The molar mass of water is 18.016 g/mol.
(36 g)/(18.016 g/mol) = 1.998 mol H₂O
Convert moles of water to moles of hydrogen by using the mole ratio. By looking at the chemical equation, you can see that for every 2 moles of water consumed, 2 moles of hydrogen is produced.
(1.998 mol H₂O) × (2 mol H₂/2 mol H₂O) = 1.998 mol H₂
Now that you have moles of hydrogen, you can convert to grams. The molar mass of hydrogen is 1.008 g/mol.
(1.998 mol) × (1.008 g/mol) = 2.01 g H₂
You will produce 2.01 grams of hydrogen
In the laboratory you dissolve 18.7 g of copper(II) bromide in a volumetric flask and add water to a total volume of 375mL.
Required:
a. What is the molarity of the solution?
b. What is the concentration of the copper(II) cation?
c. What is the concentration of the acetate anion?
Answer:
a) - 0.2 M
b) - 0.2 M
c)- 0
Explanation:
The chemical formula of copper (II) bromide is CuBr₂. Its molar mass (MM) is calculated as follows:
MM(CuBr₂)= MM(Cu) + (2 x MM(Br) = 63.5 g/mol + (2 x 80 g/mol)= 223.5 g/mol
a). Molarity = moles CuBr₂/1 L solution
moles CuBr₂ = mass/MM = 18.7 g x 1 mol/223.5 g = 0.084 mol
Volume in L = 375 mL x 1 L/1000 mL = 0.375 L
M = 0.084 mol/(0.375 L) = 0.223 M ≅ 0.2 M
b). When is added to water, CuBr₂ dissociates into ions as follows:
CuBr₂ ⇒ Cu²⁺ + 2 Br⁻
We have 1 mol Cu²⁺ (copper (II) cation) per mol of CuBr₂. Thus, the concentration of copper (II) cation is:
0.2 mol CuBr₂ x 1 mol Cu²⁺/mol CuBr₂ = 0.2 M
c). The concentration of acetate anion is 0. There is no acetate anion in the solution (the anion from CuBr₂ is bromide Br⁻).
What does wadding do?
Answer:
Wadding is a disc of material used in guns to seal gas behind a projectile or to separate powder from shot. ... Wadding for muzzleloaders is typically a small piece of cloth, or paper wrapping from the cartridge.
Explanation:
How many carbon atoms are in vitamin c?
Answer:
molecules can be much bigger. one molecule of vitamin c is made up of 20 atoms (6 carbons, 8 hydrogens, and 6 oxygens
How many molecules of NH3 are produced from 8.01x10-4g of H2
Answer:
1.61 x 10²⁰ molecules
Explanation:
Given parameters:
Mass of the hydrogen gas = 8.01 x 10⁻⁴g
Unknown
Number of molecules of NH₃ = ?
Solution:
Given reaction:
N₂ + 3H₂ → 2NH₃
We have to solve from the known to the unknown
The known specie is the mass of H₂ ;find the number of moles of the specie;
number of moles = [tex]\frac{mass}{molar mass}[/tex]
Molar mass of H₂ = 2(1) = 2g/mol
Number of moles = [tex]\frac{0.0008}{2}[/tex] = 0.0004mol
3 moles of H₂ will produce 2 moles of NH₃0.0004 moles of H₂ will produce [tex]\frac{0.0004 x 2}{3}[/tex] = 0.00027moles of NH₃
1 mole of a substance contains 6.02 x 10²³ molecules
0.00027mole of NH₃ will contain 0.00027 x 6.02 x 10²³
= 1.61 x 10²⁰ molecules
Which is the best molecule to build collegen, muscle repair, and tendon repair?
a
carohydrates
b
lipids
c
nucleic acids
d
Proteins
Answer:
d
Explanation:
collagen is made of proteins
Define dynamic equilibrium.
a) no reactants react no products are formed the rate of the forward reaction
b) is faster than the rate of the reverse reaction the rate of the reverse reaction
c) is faster than the rate of the forward reaction the rate of the forward reaction
d) equals the rate of the reverse reaction
Answer:
d) The rate of forward reaction equals the rate of the reverse reaction
Explanation:
A dynamic equilibrium is attained when the rate of forward reaction is the same as reverse reaction. It occurs majorly in a reversible reaction. Thus, no change occurs in the reaction.
The process can be control by the immediate removal of the product as it is formed. This ensure that the reaction stops when all reactants are used up.
Gaseous butane, CH3(CH2)2CH, reacts with gaseous oxygen gas, O2, to produce gaseous carbon dioxide, CO2, and gaseous water, H2O. If 51.9 g of carbon dioxide is produced from the reaction of 34.29 g of butane and 165.7 g of oxygen gas, calculate of the percent yield of carbon dioxide. Be sure your answer has the correct number of significant digits in it. (first balance the equation below) CH3(CH2)2CH3+O2−−−>CO2+H2O
Answer:
Percentage yield of carbon dioxide is 49.9%
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
2CH3(CH2)2CH3 + 13O2 —> 8CO2 + 10H2O
OR
2C4H10 + 13O2 —> 8CO2 + 10H2O
Next, we shall determine the masses of butane and oxygen that reacted and the mass of carbon dioxide produced from the balanced equation. This is illustrated below:
Molar mass of butane C4H10 = (12×4) + (10×1)
= 48 + 10
= 58 g/mol
Mass of C4H10 from the balanced equation = 2 × 58 = 116 g
Molar mass of O2 = 16 × 2 = 32 g/mol
Mass of O2 from the balanced equation = 13 × 32 = 416 g
Molar mass of CO2 = 12 + (16×2)
= 12 + 32
= 44 g/mol
Mass of CO2 from the balanced equation = 8 × 44 = 352 g
Summary:
From the balanced equation above,
116 g of butane reacted with 416 g of oxygen to produce 352 g of carbon dioxide.
Next, we shall determine the limiting reactant. This can be obtained as follow:
From the balanced equation above,
116 g of butane reacted with 416 g of oxygen.
Therefore, 34.29 g of butane will react with = (34.29 × 416) / 116 = 122.97 g of oxygen.
From the calculation made above, we can see clearly that only 122.97 g out of 165.7 g of oxygen reacted completely with 34.29 g of butane. Therefore, butane is the limiting reactant and oxygen is the excess reactant.
Next, we shall determine the theoretical yield of carbon dioxide.
In this case, we shall use the limiting reactant because it will give the maximum yield of carbon dioxide as all of it is used up in the reaction.
The limiting reactant is butane and the theoretical yield of carbon dioxide can be obtained as follow:
From the balanced equation above,
116 g of butane reacted to produce 352 g of carbon dioxide.
Therefore, 34.29 g of butane will react to produce = (34.29 × 352) / 116 = 104.05 g of carbon dioxide.
Therefore, the theoretical yield of carbon dioxide is 104.05 g
Finally, we shall determine the percentage yield of carbon dioxide as follow:
Actual yield of carbon dioxide = 51.9 g
Theoretical yield of carbon dioxide = 104.05 g
Percentage yield of carbon dioxide =?
Percentage yield = Actual yield /Theoretical yield × 100
Percentage yield of carbon dioxide = 51.9 / 104.05 × 100
Percentage yield of carbon dioxide = 49.9%
Calculate the volume in mL of a 3.25 M solution of Al2(SO4)3 needed to provide 110 g of solute. ______ mL
Answer:
Approximately [tex]92.9\; \rm mL[/tex].
Explanation:
Look up relevant relative atomic mass data on a modern periodic table:
[tex]\rm Al[/tex]: [tex]26.982[/tex].[tex]\rm S[/tex]: [tex]32.06[/tex].[tex]\rm O[/tex]: [tex]15.999[/tex].Calculate the formula mass of [tex]\rm Al_2(SO_4)_3[/tex]:
[tex]M(\mathrm{Al_2(SO_4)_3}) = 2 \times 26.982 + 3 \times (32.06 + 4 \times 15.999) = 342.132\; \rm g \cdot mol^{-1}[/tex].
Calculate the number of moles of [tex]\rm Al_2(SO_4)_3[/tex] formula units that corresponds to [tex]110\; \rm g[/tex]:
[tex]\displaystyle n(\mathrm{Al_2(SO_4)_3}) = \frac{m}{M} = \frac{110\; \rm g}{342.132\; \rm g \cdot mol^{-1}} \approx 0.322\; \rm mol[/tex].
Calculate the volume of a [tex]3.25\; \rm M[/tex] [tex]\rm Al_2(SO_4)_3[/tex] solution that would contain [tex]0.322\; \rm mol[/tex] of [tex]\rm Al_2(SO_4)_3\![/tex] formula units. Note, that the unit of concentration "[tex]\rm M[/tex]" is equivalent to [tex]\rm mol \cdot L^{-1}[/tex].
[tex]\displaystyle V = \frac{n}{c} = \frac{0.322\; \rm mol}{3.25\; \rm mol \cdot L^{-1}} \approx 0.0989\; \rm L[/tex].
Convert that to milliliters as requested:
[tex]\displaystyle V \approx 0.0989\; \rm L \times \frac{1000\; \rm mL}{1\; \rm L} = 98.9\; \rm mL[/tex].
A stable atom of sodium contains 11 protons, 11 electrons, and 12 neutrons. Which is the composition of an ion of sodium?
A. 10 protons, 11 electrons, 12 neutrons
B. 11 protons, 11 electrons, 13 neutrons
C. 11 protons, 10 electrons, 12 neutrons
D. 12 protons, 11 electrons, 12 neutrons
please answer these questions properly. I will mark brainiest for the proper answer and pleaaaaaaaaaaaase answer if you know the answer only. if u don't know the answer, leave it please. instead of writing the answer as "sorry I did not understand :)
Answer:
the first three are physicsa, and last 1 is physical the other two are chemical
Explanation:
Atmospheric pressure arises due to the force exerted by the air above the Earth. At higher altitudes, the mass of the air above the Earth is _____ than at sea level, and atmospheric pressure therefore _____ with altitude.
Answer:
less, decreases
Explanation:
When the pressure of an atmosphere occurs because of the force exerted so at the time of the higher altitudes, the air mass i.e. above the earth should be less as the air is attracted towards surface of an earth because of the gravity and air contains the mass that shows near the surface area so automatically the air density reduced due to which the mass also decreased