Answer:
-20.2 * 10^-18 J
Explanation:
From;
E = hc/λ
h= planks constant = 6.6 * 10^-34 Js
c= speed of light = 3 * 10^8 ms-1
λ = wavelength = 10.8 * 10^-9 m
Substituting values;
E = 6.6 * 10^-34 * 3 * 10^8/ 10.8 * 10^-9
ΔE = -1.8 * 10^-17 J
But for ground state E1=−13.6eV or -2.176 * 10^-18 J
From;
ΔE = E4 - E1
E4 = ΔE + E1
E4 = (-1.8 * 10^-17) + (-2. 176* 10^-18)
E4 = -20.2 * 10^-18 J
Which object is an insulator?
A. Iron
B. Copper
C. Plastic
D. Salt water
Answer:
c. plastic is an insulator
Explanation:
a and b are metals which are conductors and d contains water which is also a conductor
What is the chemical equation( formula ) of the reaction of photosynthesis
Answer:
The process of photosynthesis is commonly written as: 6CO2 + 6H2O → C6H12O6 + 6O2.
Explanation:
This means that the reactants, six carbon dioxide molecules and six water molecules, are converted by light energy captured by chlorophyll (implied by the arrow) into a sugar molecule and six oxygen molecules, the products.
heyyyyyyy......................
Answer:
helllllooooooo hi how is life
Answer:
hiiii
Explanation:
The most stable group of elements on the periodic table is the?
A) halogens
B) noble gases
C) alkali earth metals
D) alkaline earth metals
Answer:
Noble Gases B
Explanation:
The noble gases are the chemical elements in group 18 of the periodic table. They are the most stable due to having the maximum number of valence electrons their outer shell can hold. Therefore, they rarely react with other elements since they are already stable.
true or false: ur hearts a muscle
Answer: True
Explanation:
asthenosphere
OA.
oceanic continental convergent boundary
B.
oceanic-oceanic convergent boundary
O c.
divergent boundary
D.
transform boundary
Awnser I know if ur right I’ll mark brainlesst
Answer:C
Explanation:The samples are composed of different proportions of copper and zinc
i need help people :0
A laboratory hydrogen generator collects the gas produced by bubbling it through water. The total pressure of the gas collected is 751 mmHg. The temperature is 34 °C, at which water vapor pressure is 40.0 mmHg. Calculate the partial pressure of the hydrogen.
Answer:
[tex]711\ \text{mmHg}[/tex]
Explanation:
[tex]P_{total}[/tex] = Total pressure = 751 mmHg
[tex]P_{water}[/tex] = Vapor pressure = 40 mmHg
[tex]P_{gas}[/tex] = Pressure of gas
The total pressure in a system is given by Dalton's law
[tex]P_{total}=P_{gas}+P_{water}\\\Rightarrow P_{gas}=P_{total}-P_{water}\\\Rightarrow P_{gas}=751-40\\\Rightarrow P_{gas}=711\ \text{mmHg}[/tex]
The partial pressure of the hydrogen is [tex]711\ \text{mmHg}[/tex]
Compare the viscosity property of solid and liquid.
Answer
There is nothing like viscosity in solid because most of the solids usually have a rigid body. This is due to strong intermolecular forces. And it is due to this strong force between the molecules that they are unable to move and they remain fixed at their position. Some solids such as graphite which have layered structure, don't possess the property of viscosity, because of the strong force between the layers.
Explanation:
Viscosity is the property of a fluid that opposes the relative motion between two surfaces of the fluid that are moving at different velocities. In simple terms, viscosity means friction between the molecules of fluid.
FOR EXAMPLE
water is "thin", having a low viscosity, while vegetable oil is "thick" having a high viscosity
1. Calculate the amount of heat required for 25.0 grams of water tochange from 10 degrees Celsius to 30 degrees Celsius.
2. 50.0 grams of water at 100 degrees Celsius evaporated to water vapor 2 points
at 100 degrees Celsius. Calculate the amount of heat required for this
conversion.
3. A student measured 15.0 grams of ice in a beaker. The beaker was then
placed on a hot plate where it was heated uniformly for a certain amount
of time. During the melting process of the ice, the student noted that the
temperature was at 0 degree Celsius. When all the ice converted to water,
the final temperature was also at 0 degree Celsius. How much heat was
used to melt the ice?
4. If 5.0 grams of water was cooled from 50 degrees Celsius to 40
degrees Celsius, then calculate the amount of heat released by the water.
5. A certain amount of water used exactly 84.0 Joules of heat energy to
change from 25.0 degrees Celsius to 35 degrees Celsius. How many
grams of water was used?
Please help me
Answer:
Explanation:
1 )
amount of heat required = mass x specific heat x rise in temperature
= 25 x 4.2 x 20 = 2100 J .
2 )
Amount of heat required
= mass x latent heat of vaporisation
= 50 x 2260 = 113000 J .
3 )
Amount of heat required in melting the ice
= mass x latent heat of fusion
= 15 x 336 = 5040 J
4)
heat released in cooling water
= mass x specific heat x fall in temperature
= 5 x 4.2 x 10
= 210 J
5 )
amount of heat required = mass x specific heat x rise in temperature
84 = mass x 4.2 x 10
mass = 2 grams .
As you were climbing a a mountain, you noticed that rocks were crumbling below your feet and moving down the mountain. What two processes did you observe?
Answer:
Weathering and erosion
Explanation:
Weathering can be explained as the breaking down of rocks/minerals on the surface of the Earth as a result of contact with biological organism, water, air and other factors
. There are 3 common types of weathering which are;
1) physical weathering
2) biological weathering
3) chemical weathering
Erosion can be regarded as a geological process, whereby earthen material are been transported away by natural forces, these forces could be wind as well as water.
Therefore, as you were climbing a a mountain, you noticed that rocks were crumbling below your feet and moving down the mountain. What is observed are weathering and erosion processes.
After the weakening and broken up of the rock by weathering then erosion transport the bit of the rock down the mountain as you are climbing, which means the "weathering process" breakdown and the "erosion process" involves the transport or movement of the bit of the rocks
Objects with more (less or more) molecules have
heat energy than objects with (greater or fewer)
molecules? fill in the blanks
can someone help me with this
what are most of the needed formulas to find the molar volume and the molar concentration (Cm) 11th grade chemistry
Answer:
Explanation:
molar volume=moles*given volume
for molar concentration we use two formulas molarity and molality
molarity=no of moles/volume
molality=no of moles/kilogram
Put the Levels of Organization in order from the simplest (smallest) to the most complex (largest). human, brain, nervous system, nervous tissue, nerve cell
Answer:
nerve cell, nervous tissue, brain, nervous system, human.
Explanation:
The order is from the simplest to the most complex, within the simplest would be the cellular structure, then the organs come, then systems (a set of organs in multidirectional operation among them) and finally the human, which is a set of systems .
PLEASE HELP!
How many moles of NaOH would produce 10 moles of water in this reaction?
2NaOH + H2SO4 → Na2SO4 + 2H20
Answer:
The correct answer is 10
Fluorine (F) and bromine (Br) are in the same group on the periodic table. How do atoms of these elements compare when they form bonds?
Both a fluorine atom and a bromine atom lose one electron, and both atoms become stable.
A fluorine atom becomes stable by losing one electron, but a bromine atom cannot become stable by losing only one electron.
Both a fluorine atom and a bromine atom gain one electron, and both atoms become stable.
A fluorine atom becomes stable by gaining one electron, but a bromine atom cannot become stable by gaining only one electron.
Answer:
Both a fluorine atom and a bromine atom gain one electron, and both atoms become stable.
Explanation:
The two elements compare when they form bonds in that when both a fluorine atom and a bromine atom gain one electron, they both become stable.
Fluorine and bromine are elements called halogens. They both belong to group 7 on the periodic table. When they gain an electron each, they become isoelectronic with a corresponding noble gas. This gives their atom special stability.Answer:
3) Both a fluorine atom and a bromine atom gain one electron, and both atoms become stable
Explanation:i got it right on the quiz
hope this helps
Which of these could create static electricity?
A.Plugging in a vacuum
B.Running a blender
C.Combing one's hair
D.Turning on a car
c well actually I remember being tought this but I cant remember it 100
PLEASE HELP ME ANSWER THE TWO MULTIPLE CHOICE QUESTIONS!!!
ITS FOR CHEM:(
I’LL GIVE BRAINIEST:)
Answer:
4.D. 2KJ
5.B. close to 0 degree celsius
Explanation:
heat absorbed= heat given out
100g * 4.2 * (x-0)= 400g * 4.2* ( 20-x) where x is the new temp reached
then x= 20
i.e. the temperature of ice increases to 5 degree celsius and the temperature of water decreases to 5 degree celsius .
hope it helps
A gas occupies 3.5L at 2.5 kPa pressure. What is the volume at 100 mmHg at the same temperature? Be sure to
show the setup and the final answer and unit.
Show Your Work
The volume at 100 mmHg : 0.656 L
Further explanationBoyle's Law
At a constant temperature, the gas volume is inversely proportional to the pressure applied
[tex]\rm p_1V_1=p_2.V_2\\\\\dfrac{p_1}{p_2}=\dfrac{V_2}{V_1}[/tex]
V₁=3.5 L
P₁=2.5 kPa=18,7515 mmHg
P₂=100 mmHg
[tex]\tt \dfrac{18.7515}{100}=\dfrac{V_2}{3.5}\\\\V_2=\dfrac{18.7515\times 3.5}{100}=0.656~L[/tex]
Chemical and physical element properties are determined by their valence electrons. How do you describe metals with only one valence
electron?
A .highly reactive
B. poor conductors of electricity
C. reactive with other metals
D. likely to gain more electrons
Answer:
B
Explanation:
Chemical and physical element properties are determined by their valence electrons metals with only one valence electron are poor conductors of electricity. Option B is correct.
What are valance electrons?Valence electrons are the electrons present at the valance shell or orbit of the atom and always take part in the chemical reaction or reaction with other metals and can conduct electricity.
If the atom contains only one valance electron in the outermost shell or valance shell then it cannot conduct the electricity properly due to the fewer number of electrons.
Therefore, Option B is correct. Chemical and physical element properties are determined by their valence electrons metals with only one valence electron are poor conductors of electricity.
Learn more about valance electrons, here:
https://brainly.com/question/866518
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which statement is true of the particles that make up a substance?
a. Particles in a liquid and particles in a solid have the same amount of energy
b. Particles in a solid have more energy than particles in a gas
c. Particles in a gas have more energy than particles in a liquid
d. Particles in a liquid have more energy than particles in a gas.
Answer: particle in gas have more energy than the particles in a liquid
Explanation: this is because the amount of energy is directly proportional to how random the system is. gaseous molecules are in a more constant random motion than the liquid molecules
what are the 3 types of bonds in chemistry? and how can you tell when a chemical has that bond?
Answer:
Ionic bonding, Covalent bonding, Metallic bonding.
» My memory
A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds. The bond may result from the electrostatic force of attraction between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bonds. » Wikipedia
How much water (H2O ) would form if 4.04 g of hydrogen (H2) reacted with 31.98 g of oxygen (O2 )?
(2H2 + O2 2H2O)
Answer:
Mass = 36 g
Explanation:
Given data:
Mass of water formed = ?
Mass of hydrogen = 4.04 g
Mass of oxygen = 31.98 g
Solution:
Chemical equation:
2H₂ + O₂ → 2H₂O
Number of moles of hydrogen:
Number of moles = mass/molar mass
Number of moles = 4.04 g/ 2 g/mol
Number of moles = 2.02 mol
Number of moles of oxygen:
Number of moles = mass/molar mass
Number of moles = 31.98 g/ 32 g/mol
Number of moles = 1.0 mol
Now we will compare the moles of water with hydrogen and oxygen.
O₂ : H₂O
1 : 2
H₂ : H₂O
2 : 2
2.02 : 2.02
Number of moles of water formed by oxygen are less thus oxygen will limiting reactant.
Mass of water:
Mass = number of moles × molar mass
Mass = 2 mol × 18 g/mol
Mass = 36 g
1. What is the name of the ion formed from the sulfur atom?
Sulfuride
Sulfurous
Sulfur
Sulfide
2. Which of the following elements does not form an ion with a charge of +1
A:Sodium
B:Fluoride
C;Potassium
D:Hydrogen
3. The chemical properties of an element are largely determined by____
A:The number of valence electrons they have
B:The number of total protons the element has
C:The number of total ions the element has
D:The number of total electrons the element has
5. How does magnesium obey the octet rule when reacting to form compounds?
A. It gives up electrons
B. Magnesium does not obey the octet rule.
C. It gains electrons
D. It does not change its number of electrons
6. How many electrons does strontium have to give up to achieve a noble gas electron configuration?
0
1
2
3
Answer:
1 sulfide
2 Fluoride
3 A
5 A
6 2
How do I find the formula for Phosphorus Tetroxide
what is the soul of water?
Answer:
soul eater is a social enterprise
Explanation:
they donate a minimum of 10 percent to the soul community . soul water was born from the idea that everyone should be able to enjoy quality drinking tap water
how many significant figures are in 0.00970 g?
Answer:
3
Explanation:
begining 0's are never significant
all numbers 1-9 are always significant
ending 0's are only significant when there is
a decimal.
Urgent !!!!!!!!!! Due today plzzzzz help me
Answer:
Explanation:
a. H3O+
b. H3O+
c. CH3C(OH2)+
Help please !
A
B
C
D
Answer:
the answer is letter B. the entropy