Answer:
Magnesiums atomic number is 12
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God bless!
informative essay on bohrs Thomson's and rutherford model of the atom
Which element contains four electrons in its third and outer main energy level?
Answer:
valence electrons
Explanation:
The valence electrons are the outer most electrons and the principal energy level in which they belong will vary for .
The chemical element which contains four (4) electrons in its third and outer main energy level is: Silicon (Si).
An electron shell can be defined as the outermost shell of an atom of a chemical element around the atomic nucleus.
Hence, an electron shell is an orbital that is typically accompanied by electrons around the nucleus of an atom.
A sublevel is also referred to as an orbital and it can be defined as an energy level that is associated with the electrons found outside the atomic nucleus.
In Chemistry, there are four main (4) types of sublevel and these are:
s orbital (sublevel): it has one (1) orbital i.e 1s.p orbital (sublevel): it has three (3) orbitals.d orbital (sublevel): it has five (5) orbitals.f orbital (sublevel): it has seven (7) orbitals.In the third (3rd) energy level, there are only three (3) sublevels and these are; s, p and d sublevels.
Silicon is a chemical element that is found in group (4) of the periodic table because it has four (4) electrons in its third and outermost shell.
In its ground state, Silicon (Si) contains the following number of electrons:
Two electrons in its first (n = 1) energy level. Eight electrons in the second (n = 2) energy level.Lastly, it contains four (4) electrons in its third (n = 3) and outer main energy level.Read more: https://brainly.com/question/18214726
A chemist decomposes samples of several compounds; the masses of their constituent elements are listed. Calculate the empirical formula for each compound.
a. 1.245 g Ni, 5.381 g I,
b. 2.677 g Ba, 3.115 g Br,
c. 2.128 g Be, 7.557 g S, 15.107 g
Answer:
you can see the empirical formula at the pic
The empirical formula for compound (a) is NiI2, (b) is BaBr2 and (c) is BeS.
What is empirical formula?
Empirical formula of a compound is defined as the simplest whole number ratio of atoms present in a compound.
(a) 1.245 g Ni : 5.381 g I
Mole of Ni ; Mole of I = 1.245/59 : 5.381/127 = 0.02 : 0.04 = 1:2
So the formula is NiI2
(b) 2.677 g Ba : 3.115 g Br
Mole of Ba : Mole of Br = 2.677/137 : 3.115/60 = 0.019 : 0.038
= 0.02 : 0.04 = 1:2
So the formula is BaBr2
(c) 2.128 g Be : 7.557 g S
Mole of Be : Mole of S = 2.128/9 : 7.557/32 = 0.2 : 0.2 = 1:1
So the formula is BeS
Thus, empirical formula for compound (a) is NiI2, (b) is BaBr2 and (c) is BeS.
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How would you calculate an object's mechanical energy?
a. Add its kinetic and potential energies. b. Multiply its kinetic and potential energies.
c. Subtract its kinetic energy from its kinetic energy.
d. Subtract its potential energy from its kinetic energy.
Answer:
You would add its kinetic and potential energies.
Explanation:
Hope this helps!! :)
Answer:
A) Add its kinetic and potential energies
Explanation:
I got it right on Edge 2022
Which Drug is used not to cure Cancer, but can kill Cancer?
(A) = Adrenaline.
(B) = Burger King.
(C) = Chemotherapy.
(D) = Deoxyribose.
(E) = Ethanol.
Answer:
chemotherapy
Explanation:
If your hypothesis is incorrect you should...
Condensation occurs with the removal of thermal energy.
True or False? If false, rewrite to make the question true.
PLZZZ HELP
Answer:
true
Explanation:
Condensation is the opposite of vaporization. True. When does condensation occurs, does a gas lose or gain thermal energy?
Answer:
True
Explanation:
Condensation is formed with moisture and cold air, so the removal of thermal energy, or heat, would create the perfect conditions :)
List the steps in the water cycle, in the correct order?
PLSSS HELP Match each image to the
correct step of meiosis. PLS HELP
Answer:
Explanation:
Here you go!! Hope this helps.
A substance that is dissolved in a solution is called a(n) __________________.
solute
compound
ion
Answer:
solute
Explanation:
Which is NOT an example of plants demonstrating the characteristics of life?
A. Plants are forces to make adaptations depending on its environment
B. A plant has stimuli that cause it to grow towards the sun
C. There are stages of growth that plants go through depending on favorable conditions
D. The leaves on a plant move in reaction to the wind
Answer:
D
Explanation:
trust me bro ive done this
Option D does not represent an example of plants demonstrating the characteristics of life.
The following information should be considered:
Plants to be treated as the forces for making the adaptions and based on the environment. The plant contains stimuli that result to grow towards the sun. There should be the growth stages based on the favorable conditions.Therefore we can conclude that Option D does not represent an example of plants demonstrating the characteristics of life.
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Determine the mass (in grams) of NaCl in 294 grams of a 24.1% (m/m) NaCl solution. Be sure to report to the correct number of significant figures with no units.
I NEED HELP WITH THIS URGENTLY!!!!!
Answer:
70.9 grams 3 sig figs
Explanation:
24.1% of 294 grams = 0.241(294 gram) = 70.854 grams ≅ 70.9 grams 3 sig figs
True or false: BrF5(aq) is a good insulator.
Answer:
true
hope this helps :)
Explanation:
True, [tex]BrF_5[/tex] (aq) is a good insulator.
What is an insulator?A material or an object that does not easily allow heat, electricity, light, or sound to pass through it.
Bromine pentafluoride appears as a colourless, fuming liquid with a pungent odour. Used to make other chemicals and in rockets.
Hence, [tex]BrF_5[/tex] (aq) is a good insulator.
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Please tell me the answers to A, B, and C
Answer:
A=element
B=compond
C=solution
The indicator dilution method is a technique used to determine flow rates of fluids in channels for which devices like rotameters and orifice meters cannot be used (e.g., rivers, blood vessels, and large- diameter pipelines). A stream of an easily measured substance (the tracer) is injected into the channel at a known rate and the tracer concentration is measured at a point far enough downstream of the injection point for the tracer to be completely mixed with the flowing fluid. The larger the flow rate of the fluid, the lower the tracer concentration at the measurement point. A gas stream that contains 1.50 mole% CO2 flows through a pipeline, Twenty (20.0) kilograms of CO2 per minute is injected into the line. A sample of the gas is drawn from a point in the line 150 meters downstream of the injection point and found to contain 2.3 mole% CO2.(a) Estimate the gas flow rate (k mol/min) upstream of the injection point.(b) Eighteen seconds elapses from the instant the additional CO2 is first injected to the time the CO2 concentration at the measurement point begins to rise. Assuming that the tracer travels at the average velocity of the gas in the pipeline (i.e., neglecting diffusion of CO2), estimate the average velocity (m/s), if the molar gas density is 0.123k mol/m3 what is the pipe diameter?
Answer:
[a]. 55.5kmol/min.
[b]. The average velocity = 8.3m/s.
pipe diameter = 1.0954m.
Explanation:
So, from the question above we are given the following data or information or parameters which are going to help us in solving the above question;
=> ''A gas stream that contains 1.50 mole% CO2 flows through a pipeline''
=> ''Twenty (20.0) kilograms of CO2 per minute is injected into the line.''
=> '' . A sample of the gas is drawn from a point in the line 150 meters downstream of the injection point and found to contain 2.3 mole% CO2''
=> ''molar gas density is 0.123k mol/m3''
[a].The gas flow rate (k mol/min) upstream of the injection point can be calculated as follows.
- Determine the mass balance= j₁ +[ 20 /.123 × 44] = j₃. Thus, the flow gas rate is given as;
w₁ × 1.50 mole% CO2 + 3.6954= 2.3 mole% CO2 × w₃.
-3.610 = - 0.008w₁.
w₁ = 451.3 m³/min.
Thus, the flow rate = 0.123 × 451.3 = 55.51 kmol/min.
[b]. The average velocity = 150/ 18 seconds = 8.3 m/s.
[c]. Pipe Diameter can be calculated as follows;
0.123 × 8.3 × [3.12 × (pipe diameter)² / 4] = 55.51/60.
[1.0209 × 3.12]/4 × [pipe diameter]² = 0.9252.
0.8014065 × [pipe diameter]² = 0.9252.
[pipe diameter]² = 0.9252/ .8014065.
[pipe diameter]² = 1.15443.
[pipe diameter] = √1.15443.
[pipe diameter] = 1.2 m² = 1.0954m.
A) The gas flow rate (k.mol/min) upstream of the injection point is;
55.51 k.mol/min
B) The average velocity and the diameter of the pipe are respectively;
8.33 m/s and 1.072 m
Gas Flow rate in thermodynamics
Due to the fact that there is no reaction or accumulation in the pipeline, we can say that the input of CO₂ is equal to it's output. Thus;
Upstream + Injection = Downstream
A) If we assume that x is the flow rate of gas (kmol/min), then there is the we can write the balance as:
0.015x + (20/44) = 0.023(x + 20/44)
Expanding gives us;
0.015x + 0.4545 = 0.023x + 0.01045
Solving for x gives;
x = 55.51 kmol/min
B) Formula for velocity is;
v = distance/time
Thus, since the length of the pipe is 150 m/s and time is 18 seconds, then velocity is;
v = 150/18
v = 8.33 m/s
Now, volumetric flow rate is calculated from;
Q = q' * ρ
where;
q' is gas flow rate
ρ is gas density
Thus;
Q = 55.51 * 0.123
Q = 451.3 m³/min = 7.522 m³/s
We can also express average velocity as;
v = Q/A
where A is area = πD²/4
Thus;
8.33 = 7.522/(πD²/4)
Making D the subject of the formula gives;
D = √((4 * 7.522)/(8.33π))
D = 1.072 m
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Define waves in your own words.
Answer:
Waves is the disturbance or variation that transfer energy from one location to other
Answer:
this is not in my words but i think this will help
(put some of the words you would use in this)
Explanation:
Transverse waves are always characterized by particle motion being perpendicular to wave motion. A longitudinal wave is a wave in which particles of the medium move in a direction parallel to the direction that the wave moves. ... Longitudinal waves are always characterized by particle motion being parallel to wave motion.
hope i helped
How many molecules are there in 985 mL of nitrogen at 0.0 degrees C and 1.00x10^-6 mm Hg?
(It would be better if work or steps to solve problem are given but if not its fine).
Answer:
3.48 x 1013 N2 molecules
step-by-step explanation:
Lets set up our equation first
P = 1.00 x 10-6 mm Hg T = 0.0° C + 273 = 273 K
We are given the V = 985 mL ,
R = 0.0821 L·atm/mol·K
Now use the ldeal gas law, but we are solving n, amount of substanvce
PV = nRT, we will change this equation to ;
n = PV/RT
n = 1.00 x 10-6 mm x 1 atm/760 mm x 985 mL x 1 L/103
mL/
(0.0821 L·atm/mol·K x 273 K) = 5.78 x 10-11 moles N2
nmolecules = 5.78 x 10-11 moles N2 x 6.02 x 1023 N2 molecules/1 mol N2
Calculate the final volume of a solution prepared by diluting a 4.0 M solution with a volume of 7.0 mL to 0.80 M in milliliters.
Answer:
Explanation:
Let the final volume be v .
from the formula
S₁ V₁ = S₂V₂
4 x 7 = .8 x V₂
V₂ = 35 mL
Final volume of the solution will be 35 mL .
Help plzzzzzzzzzzzzzzz
Answer:
um wheres thepassage?
Explanation:
What do you learned about homogeneous mixture?
Answer:
homogeneous is consisting a part of or people are similar to each other or are if same type.
Particle motion in ice is __________than partlice motion in water.
1. faster
2. slower
3. the same
Answer:
1. Faster
Explanation:
I need help pls... look at photo
Answer:
LA PRIMERA ES N
Explanation:
There are approximately 250 million passenger vehicles in the United States. If each is driven 25,000 km per year, calculate the total mass of CO, NOx and HC emitted in 1970 if all vehicles just meet the government standard at that time. Please find the standard values in textbook. (Please round up to 3 decimal points and use 'E' for exponent)
Answer:
CO = 1.320 x 10¹¹ Kg
NOx = 1.942 x 10¹⁰ Kg
HC = 1.592 x 10¹⁰ Kg
Explanation:
Given that;
there are approximately 250 million passenger vehicles
each is driven 25,000 km per year which is 15534.28 miles per year
In 1970, the vehicular emission norms are;
CO = 34 g/mile , NOx = 5 g/mile , HC = 4.1 g/mile
so emission of CO in 1970 is;
250000000 × 15534.28 × 34 g
= 1.320 x 10¹⁴ g
= 1.320 x 10¹¹ Kg
Also, emission of NOx in 1970
250000000 × 15534.28 × 5 g
= 1.9417 x 10¹³ g
= 1.942 x 10¹⁰ Kg
emission of HC in 1970
= 250000000 × 15534.28 × 4.1 g
= 1.5922 x 10¹³ g
= 1.592 x 10¹⁰ Kg
Help :( the blue boxes are clickable
Answer:
I am sure they are why won't they
When an aqueous sodium hydroxide solution of sodium benzoate is acidified, what precipitate is formed, and why does it precipitate?
Answer:
Insoluble benzoic acid is formed
Explanation:
When benzoic acid is dissolved in sodium hydroxide solution, sodium benzoate is formed. This compound is highly soluble in the aqueous layer.
If this solution is now acidified, the equilibrum position shifts towards the undissociated benzoic acid and a precipitate appears.
An insoluble substance formed during crystallization or precipitation is called a precipitate. The precipitate of the reaction formed is of benzoic acid.
What is a precipitation reaction?A precipitation reaction is a type of reaction in which an insoluble salt or substance is formed as the result of the reaction between the soluble salt solutions.
The substance or the salt produced that does not get dissolved in the solution is called a precipitate.
In the reaction, benzoic acid reacts with the sodium hydroxide salt and forms sodium benzoate salt as shown,
[tex]\rm C_{6}H_{5}COOH(s) + NaOH(aq) \rightarrow C_{6}H_{5}COO^{-}Na^{+}(aq) + H_{2}O(l)[/tex]
When the salt of sodium benzoate is acidified then the precipitation of benzoic acid is formed. The precipitate occurs because the equilibrium shifts towards the undissociated benzoic acid.
Therefore, a precipitate of benzoic acid is formed.
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If 1.4434 moles of H2O are produced, how many moles of N2 will also be produced?
Answer:
1 gram of N2 is equal to 0.035697202053303 mole. i dont know the rest but intried to help
. hopefully this will give you someone else a starting point. goodluck
Identify the correct net ionic equation for the reaction that occurs when solutions of Pb(NO3)2 and NH4Cl are mixed.
Answer:
Pb2+(aq) + 2Cl–(aq) ----> PbCl2(s)
Explanation:
The net ionic equation shows the main reaction that takes place in a system. Hence, a net ionic equation focusses only on those species that actually participate in the reaction.
For the reaction between Pb(NO3)2 and NH4Cl , the net ionic equation is;
Pb^+(aq) + 2Cl^-(aq) ---> PbCl2(s)
The correct net ionic equation for the reaction that occurs when solutions of Pb(NO₃)₂ and NH₄Cl are mixed is
Pb⁺(aq) + 2Cl¯(aq) —> PbCl₂(s)To know the the correct net ionic equation for the reaction that occurs when solutions of Pb(NO₃)₂ and NH₄Cl are mixed, we shall write the net ionic equation for the reaction. This is illustrated below:
Pb(NO₃)₂(aq) —> Pb⁺(aq) + NO₃¯(aq)
NH₄Cl(aq) —> NH₄⁺(aq) + Cl¯(aq)
Pb(NO₃)₂(aq) + NH₄Cl(aq) —>
Pb⁺(aq) + NO₃¯(aq) + NH₄⁺(aq) + Cl¯(aq) —> PbCl₂(s) + NO₃¯(aq) + NH₄⁺(aq)
Cancel the spectator ions (i.e NO₃¯ and NH₄⁺) and write 2 before Cl¯ to obtain the net ionic equation as shown below:
Pb⁺(aq) + 2Cl¯(aq) —> PbCl₂(s)Thus, the correct net ionic equation for the reaction that occurs when solutions of Pb(NO₃)₂ and NH₄Cl are mixed is
Pb⁺(aq) + 2Cl¯(aq) —> PbCl₂(s)Learn more: https://brainly.com/question/21883718
Consider the balanced equation below. Upper P Upper C l Subscript 3 Baseline + Upper C l Subscript 2 Baseline right arrow Upper P Upper C l Subscript 5. What is the mole ratio of PCl3 to PCl5? 1:1 2:1 3:5 5:3
Answer : The mole ratio of [tex]PCl_3[/tex] to [tex]PCl_5[/tex] is 1 : 1.
Explanation :
Balanced chemical reaction : It is a chemical reaction in which the number of atoms of individual elements present on reactant side must be equal to the product side.
The balanced chemical reaction is:
[tex]PCl_3+Cl_2\rightarrow PCl_5[/tex]
By the stoichiometry of the reaction we can say that 1 mole of [tex]PCl_3[/tex] reacts with 1 mole of [tex]Cl_2[/tex] to give 1 mole of [tex]PCl_5[/tex].
From this we conclude that the mole ratio of [tex]PCl_3[/tex] to [tex]PCl_5[/tex] is 1 : 1.
Hence, the mole ratio of [tex]PCl_3[/tex] to [tex]PCl_5[/tex] is 1 : 1.
Answer:
A
Explanation:
What is the atomic number of arsenic (As)?
O A. 33
O B. 15
C. 75
D. 4
SUB
Answer:
33
Explanation:
When 28.0 g of acetylene reacts with hydrogen, 24.5 g of ethane is produced. What is the percent yield of C2H6 for the reaction?
C2H2(g) + 2H2(g) → C2H6(g)
Answer:
[tex]Y=75.6\%[/tex]
Explanation:
Hello.
In this case, since no information about the reacting hydrogen is given, we can assume that it completely react with the 28.0 g of acetylene to yield ethane. In such a way, via the 1:1 mole ratio between acetylene (molar mass = 26 g/mol) and ethane (molar mass = 30 g/mol), we compute the yielded grams, or the theoretical yield of ethane as shown below:
[tex]m_{C_2H_6}^{theoretical}=28.0gC_2H_2*\frac{1molC_2H_2}{26gC_2H_2}*\frac{1molC_2H_6}{1molC_2H_2} *\frac{30gC_2H_6}{1molC_2H_6}\\ \\m_{C_2H_6}^{theoretical}=32.3gC_2H_6[/tex]
Hence, by knowing that the percent yield is computed via the actual yield (24.5 g) over the theoretical yield, we obtain:
[tex]Y=\frac{24.5g}{32.3g}*100\%\\ \\Y=75.6\%[/tex]
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