Using the models of the molecules below, (H2 and CH4) what does it mean for a molecule to be symmetrical?
Answer:
A molecule is symmetrical if it can be cut into two identical halves.
Explanation:
H2 can be written as H + H
CH4 is not a symmetrical molecule
according to the Aufbau principle, which principle energy level would have higher energy, n=2 or n=5?
Answer:b
Explanation:
A drop in water temperature is observed when 0.848 g of ammonium nitrate is added. The enthalpy change for this reaction is +0.117 kJ. Calculate the Δ Hrxn, in kJ/mol, for this reaction.
The Δ Hrxn, in kJ/mol, for this reaction= 11.04 kJ/mol
Further explanationGiven
0.848 g ammonium nitrate
The enthalpy change : +0.117 kJ
Required
Δ Hrxn, in kJ/mol
Solution
Delta H reaction (ΔH) is the amount of heat change between the system and its environment
The value of ° H ° can be calculated from the change in enthalpy of standard formation:
∆H ° rxn = ∑n ∆Hf ° (product) - ∑n ∆Hf ° (reactants)
mass of NH4NO3 = 0.848 g
mol of NH4NO3(MW = 80 g/mol)
mol = 0.848 : 80
mol = 0.0106
The Δ Hrxn :
= 0.117 kJ : 0.0106 mol
= 11.04 kJ/mol
What can you determine about an element if you only know its group number on the periodic table?
A. The total number of protons and neutrons
B. The number of protons
C. The total number of electrons
D. The number of valance elctrons
Answer:
c
Explanation:
how can paper that has already been used be physically changed
Answer:
the paper could be burn up
For work to be done on an object:
*
The work input must be equal to the work output
The energy input must be equal to the energy output
Only a force must be applied, moving the object is not required
The object has to move a distance when a force is applied to it
Answer:
The object has to move a distance when a force is applied to it
Explanation:
For work to be done on a body the force applied must move the body through a particular distance.
Work done = Force x distance
If no distance is moved by the force, no work is done.
Also, the angle between the force and the distance must be 0 to do the maximum work on the body.
Why do you think there is a need for three layers in a film
Answer:
When our tear film becomes unstable, symptoms of Dry Eye can occur. OUR TEAR FILM HAS THREE LAYERS. Our tear film is made up of three layers – an oil (lipid) layer, a water (aqueous) layer and a mucin layer. ... Its main purpose is to seal the tear film which helps reduce evaporation of our natural tears.
How would you find the average speed of a marathon runner throughout an entire race? A Divide the total distance the runner travelled by the total time they took to travel that distance B Divide the total time the runner it took the runner to travel that distance by the the total distance they travelled C Multiply the total distance the runner travelled by the total time they took to travel that distance D Multiply the total time the runner it took the runner to travel that distance by the the total distnace they travelled
Answer:
distance divided by time so A
Explanation:
which atom has the smallest radius? Sr or I
Answer: Strontium has 219 pm
Iodine has 115 pm
Explanation: So the answer is Sr-Strontium
What is the percent composition of nitrogen in N 2 O
Answer:
28 %
Explanation:
Mass mass N2O = 28 + 16 = 44 mass nitrogen = 2 x 14 = 28 % nitrogen Chemistry.
how many grams is 5.16 mol br2?
Answer:
Mass = 824.57 g
Explanation:
Given data:
Mass of bromine = ?
Number of moles of bromine = 5.16 mol
Solution:
Formula:
Mass = number of moles × molar mass
Molar mass of bromine = 159.8 g/mol
by putting values,
Mass = 5.16 mol × 159.8 g/mol
Mass = 824.57 g
All atoms of oxygen have the same mass number. True or False
Answer:
pretty sure it's false
Explanation:
hope this helps!
What patterns do you notice between the three maps? Using the concepts
you've learned in this lesson, construct an explanation for these patterns in your
Science Notebook or in the space below.
Answer:
A spatial pattern is a perceptual structure, placement, or arrangement of objects on Earth. It also includes the space in between those objects. Patterns may be recognized because of their arrangement; maybe in a line or by a clustering of points.
Explanation:
How many different methods can you list for how we generate electricity in this country. Which of those methods do we use the most, and which of them should we invest more in
Answer:
1. Broadly, there are three different methods for how electricity is generated in the United States. They include; Fossil fuels, Nuclear energy, and Renewable energy sources.
2. Fossil fuels, are used the most, with Natural gas topping the list by 38%.
3. More should be invested into renewable gas. It is a clean source of energy and investing in it would bring about a cleaner and safer environment.
Explanation:
Fossil fuels arise from plants and animals that have been long dead and can can now be converted to sources of energy. Examples include; coal natural gas, crude oil. etc.
Nuclear energy arises from the fission of uranium atoms, nuclear decay, and nuclear fusion. They are safe since green house gases are not emitted. Thermal energy can be generated as the byproduct of these reactions.
Renewable sources of energy are generated from natural sources which are always available. Examples are; sun, wind, biomass, water, and geothermal sources,
Could someone help me with this thank you!
Answer:
The answer is D
I searched it up to verify.
Answer: I think the possible answer is B or D
Explanation: There are few of the energies like: Gravitational, electrical, Chemical.....
Which of the above electron dot structures is wrong?
Be
B
Al
H
Ne
Answer:
Al
Explanation:
Aluminum (Al) is in the same group as Boron (B) so it should have three electrons or dots around it.
Hope that helps.
Answer:
Structre of Al is wrong
Means Al is right answer of the above question
Explanation:
Because valence shell of aluminum contains three electron not 5 elctrons
Correct structure of Al is given
How many atoms are there in 2.0 moles of magnesium (Mg)?
A. 1.2 x 1024
B. 2.0 x 1022
C. 6.0 x 1021
D. 3.0 x 1023
Answer:
It should be 1. 1.2 X 10^24
Explanation:
I need help working these
Answer:
1) 7.80 X 10^22[tex]\frac{1}{6.02*10^{23} }[/tex] = .13
2) 5.6 [tex]\frac{6.02*10^{23} }{1}[/tex] = 3.4 X 10^24
3)3.81 [tex]\frac{1}{74.55}[/tex] X [tex]\frac{6.02*10^{23} }{1}[/tex] = 3.08 X 10^22
4) 399.91 [tex]\frac{4.05*10^{23} }{6.02*10^{23} }[/tex] = 269
5)4.32 [tex]\frac{1}{18.01}[/tex] X [tex]\frac{22.4}{1}[/tex] = 5.37
Explanation:
For 2 the correct answer is 3.4 instead of 3.2. The 3.4 is rounded from 3.37. Sadly I couldn't figure out the bonus.
PLS HELP THIS IS DUE TODAY!!
Answer:
I think it would be Yellow
What isotope of carbon is radioactive:
A) Carbon-12
B) Carbon-13
C) Carbon-14
D) Carbon-13 and Carbon-14
If 11 grams of a gas occupies 5.6 liters at STP, what is its gram molecular mass?
The molecular mass of gas = 44 g/mol
Further explanationGiven
5.6 Liters of gas
11 gram of gas
Required
The molecular mass
Solution
STP = Standart Temperature and Pressure , 1 atm 273 K
At STP , 1 mol gas = 22.4 L
So mol of 5.6 Liters gas :
= 5.6 : 22.4
= 0.25 moles
The molecular mass of gas :
= mass : mol
= 11 g : 0.25 moles
= 44 g/mol
A 15.33 g sample of magnesium oxide is found to contain 12.67 g of magnesium. What is the percent (by mass) composition of
the magnesium in the compound?
026 Ma
Answer:
Explanation:
I can help
Answer:
12.67g of Mg / 15.33g of MgO * 100% = 82.6% of Mg
Explanation:
Metals bond with halogens to form colorless metal halides. During an experiment, chlorine water was added to a solution of potassium bromide. A record of the experiment is shown.
Experimental Record
Reactants Color of Reactants Color of Reactants after Mixing
cl,
Colorless solution
Deep yellow-orange colored solution is formed
KBT Colorless solution
Which of the following conclusions can be made about this chemical reaction based on the data? (1 point)
O Chlorine is more reactive than bromine.
Potassium bromide and chlorine do not react.
O Potassium metal is formed from a single replacement reaction.
O Bromine solution is colorless and is formed due to a single replacement reaction.
Answer:
O Chlorine is more reactive than bromine.
Explanation:
From this experiment we can conclude that chlorine is more reactive than bromine and it is the reason why the reaction is able to proceed.
The reaction is a single displacement reaction in which the position of an element in the activity series is very important. Since chlorine is more electronegative and highly reactive when compared to bromine, it will displace bromine from the solution of potassium bromide. So, we have product of potassium chloride and the bromide.What kind of cell has a nonspontaneous voltage?
An electrolytic cell
A dry cell
A wet cell
A voltaic cell
Answer:
dry cell
Explanation:
because it stops when salt distribution becomes equal as bridge is not added
Answer:
a
Explanation:
a p e x :)
A. Airplanes typically fly at an altitude of about 10,000 meters. At this altitude the atmospheric pressure is significantly less than it is at sea-level. Because of this, airplane cabins must be pressurized so that the people on board can continue to get enough oxygen. If a typical 747 has a volume of 28,000 m3 and is filled with air at 101.3 kPa on the ground, what is the new volume of air inside when the cabin is pressurized to 75 kPa once it is in flight? b. Twinkies are made up of 68% air. If you buy a Twinkie in the airport and take it with you on a plane ride, how would its size change during the flight?
Answer:
The new volume of the air inside when the cabin is pressurized to 75 kPa is 37818.[tex]\overline 6[/tex] m³
Explanation:
The given 747 airplane parameters are;
The volume of air in the airplane, V₁ = 28,000 m³
The pressure of the air on the ground, P₁ = 101.3 kPa
The pressure of the air once it is in flight, P₂ = 75 kPa
Let V₂ represent the new volume of the air inside when the cabin is pressurized to 75 kPa
Boyle's Law states that the pressure of a given mass of air is inversely proportional to its volume at constant temperature
Therefore, by Boyle's law, we have;
P ∝ 1/V and P₁·V₁ = P₂·V₂
Which gives;
V₂ = P₁·V₁/P₂
Substituting the known values, we get;
V₂ = 101.3 kPa × 28,000 m³/(75 kPa) = 37818.[tex]\overline 6[/tex] m³
The new volume of the air inside when the cabin is pressurized to 75 kPa = V₂ = 37818.[tex]\overline 6[/tex] m³.
What is it that lives if it is fed, and dies if you give it a drink
Answer:
fire
Explanation:
Answer:
ants if you splash a ant with sum water that shít is dead
What is the percentage composition for H2O in this compound Al(OH)3.2H2O?
a
50.55%
b
40.05%
c
32.73 %
d
65.09%
Answer:
32.73%
Explanation:
To solve this problem, first find the molar mass of Al(OH)₃.2H₂O
Atomic mass of Al = 27g/mol
O = 16g/mol
H = 1g/mol
Molar mass = 27 + 3(16 + 1) + 2(2(1) + 16)
= 27 + 51 + 36
= 114g/mol
Percentage composition = [tex]\frac{36}{114}[/tex] x 100 = 32.73%
how many moles are represented by 3.01x10^23 helium atoms
a. 1 mole
b. 0.50 moles
c. 0.75 moles
d. 5 moles
Answer:
b. 0.50 moles
Explanation:
To solve this problem we use Avogadro's number (6.023x10²³ atoms/mol).
By dividing the number of atoms (or molecules) by that number, we can calculate how many moles they represent.
3.01x10²³ atoms ÷ 6.023x10²³ atoms/mol = 0.50 molesSo the answer is option b. 0.50 moles.
HELPPPPPPPPPP
IDENTIFY THE ELEMENT WHICH HAS A GREATER ATOMIC MASS FLOURINE OR CLOURINE
Answer:
Cu Copper 63.546
Cl Chlorine 35.453
F Fluorine 18.998403
Explanation:
I don't know whether you asked for Cu or Cl so answered it both.
how does a diaphragm help in viewing the specimen in a microscope
Answer:
Diaphragm controls the amount of light reaching the specimen. It is located above the condenser and below the stage. Most high quality microscopes include an Abbe condenser with an iris diaphragm. Combined, they control both the focus and quantity of light applied to the specimen.