Answer:
Contraction. (Science: physiology) a shortening or reduction in size, in connection with muscles contraction implies shortening and/or development of tension. Origin: L. Contractus = drawn together.
Explanation:
hope this helped:)
How do you calculate the energy, in joules, of a photon of ultraviolet light with a frequency of 6.8 x 10^15 Hz?
Answer:
E = 45.08×10⁻¹⁹j
Explanation:
Given data:
Energy of photon in joule = ?
Frequency of photon = 6.8×10¹⁵ Hz
Solution:
Formula:
E = h.f
f = frequency
h = planck's constant (6.63×10⁻³⁴Js)
E = energy
Value of planck's constant is 6.63×10⁻³⁴Js.
E = 6.63×10⁻³⁴Js ×6.8×10¹⁵ Hz
Hz = s⁻¹
E = 6.63×10⁻³⁴Js ×6.8×10¹⁵ s⁻¹
E = 45.08×10⁻¹⁹j
Energy is the quantitative unit, which is measured in joules. The energy of a photon of UV light having the frequency 6.8×10¹⁵ Hz is 45.08×10⁻¹⁹ Joules.
Given:
Frequency of photon = 6.8×10¹⁵ Hz
Energy of a photon in joule =?
Usingt the formula of energy:
E = h x v
where,
v = frequency
h = planck's constant (6.63×10⁻³⁴Js)
E = energy
Substituting the values in the equation, we get:
E = 6.63×10⁻³⁴Js ×6.8×10¹⁵ Hz
E = 6.63×10⁻³⁴Js ×6.8×10¹⁵ s⁻¹
E = 45.08×10⁻¹⁹ Joules
Therefore, the energy of a photon in the UV region is 45.08×10⁻¹⁹ Joules
To know more about energy, refer to the following link:
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The man who was first to see living microorganisms in his pond water was who?
Alveolar air (a mixture of nitrogen, oxygen, and carbon dioxide) has a total pressure of 0.998 atm. If the partial pressure of oxygen gas is 0.198 atm and the partial pressure of nitrogen gas is 0.770 atm, what is the partial pressure of carbon dioxide in millimeters of mercury?
Answer:
22.8 mmHg
Explanation:
According to Dalton's law of partial pressures, the total pressure of a mixture of gases is obtained as the sum of the partial pressures if all the individual gases present in the mixture.
Since the total pressure of gases in the mixture is 0.998 atm, the partial pressure of carbon dioxide is;
PCO2 = [Ptotal - (PO2+ PN2)]
Hence;
PCO2 = [0.998 - (0.198 + 0.770)]
PCO2 = 0.03
Since
1 atm = 760 mmHg
0.03 atm = 0.03 × 760 /1
=22.8 mmHg
A chemist is trying to classify an unknown substance as either a metal or nonmetal. What question should the chemist use to help classify the material?
A. Does the material feel hard to the
touch?
B. Does the material feel rough or smooth?
C. Is the material a good conductor or a poor conductor?
D. Will the material float in water?
Please Help me!!!
Answer:
c
Explanation:
metals are good conductors, while non metals are not good conductors
Water and chemical elements move through cycles called biogeochemical cycles. Select the best way to explain biogeochemical cycles. a. When chemicals move from the atmosphere to a living organism. b. When a chemical moves from an organism to the atmosphere then back to an organism. c. When organisms move from an organism to the atmosphere then back to an organism.
Answer:
When a chemical moves from an organism to the atmosphere then back to an organism.
Explanation:
If we look at it closely, geology and chemistry play major roles in the process of movement and recycling of inorganic matter between living organisms and their environment. This has been called the biogeochemical cycle.
Biogeochemical cycles involve movement of chemical elements among the biotic and abiotic components of the environment; from atmosphere to land to sea, and from soils to plants.
help please
1. Covalent Bonds are formed when atoms
A. Give Electrons
B. Share Electrons
C. Take Electrons
Answer:
b. share electrons
Explanation:
How would you calculate the gravitational potential energy of a 2 kg bottle of soda falling off of a kitchen table that is 0.76 m tall ?
Answer:
14.9 Joules .
Explanation:
P. E. = m g h
= 2 * 9.8 * 0.76
= 14.9 Joules to the nearest tenth.
Answer:
2*0.76*97
Explanation:
Water and salt are compounds made of the combination of more than one type of atom. Which statement is false?
A. Because they they are are compounds, compounds, they they cannot cannot be be pure pure substances.
B. Both compounds compounds are are considered considered pure pure substances.
C. These compounds compounds have have specific specific physical physical properties properties that that never never change.
D. These compounds compounds have have distinct distinct chemical chemical properties.
Compounds are made of the various elemental atoms joined together. Water and salt are compounds that can be present in their pure form. Thus, option A is false.
What are compounds and pure substances?A compound is a substance formed by the bond between the atoms of the elements that shares, transfers, donates, or gains electrons to join and interlink chemically.
The pure substance is characterized by the presence of only a single type atom of the element. They have invariability and can exist in various phases with constant composition.
Water and salt are compounds made of two or more atoms of different elements that have specific physical properties and distinct chemical properties.
Therefore, option A. the compounds cannot be pure substances is false.
Learn more about pure substance here:
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How much sunlight is there in the transition zone. For science.
Answer:
Transition zone of the sun
Explanation:
Transition Region - The transition region is a very narrow (60 miles / 100 km) layer between the chromosphere and the corona where the temperature rises abruptly from about 8000 to about 500,000 K (14,000 to 900,000 degrees F, 7700 to 500,000 degrees C).
Nitrogen (N) is element number 7 in the periodic table. It has a mass number of 14. Nitrogen
has gained 3 electrons. Nitrogen is a/an___.
a. Anion
bcation
c. Isotope
d. All of the above
The isotope Np-238 has a half life of 2.0 days if 96 grams of it were present on Monday how much will remain six days later
Answer:
12 grams
Explanation:
For any radioactive substance
the amount of substance left after n half life is given by = [tex]x/2^n[/tex]
where x the original amount of substance.
____________________________________________
Half life of isotope Np-238 = 2 days
total no of days = 6
no of half life =total no of days/Half life of isotope Np-238 = 6/2 = 3
thus,
for our problem n = 3
initial amount of Np-238 = 96 grams
thus,
the amount of substance left after 3 half life = 96/2^3 = 96/8 = 12 grams.
Thus, 12 grams will be left after six days.
The isotope Np-238 has a half life of 2.0 days if 96 grams of it were present on Monday how much will remain six days later
Answer:
12.02 g
Explanation:
From the question given above, the following data were obtained:
Half life (t½) = 2 days
Original amount (N₀) = 96 g
Time (t) = 6 days
Amount remaining (N) =..?
Next, we shall determine the rate of disintegration of the isotope. This can be obtained as follow:
Half life (t½) = 2 days
Decay constant (K) =?
K = 0.693 / t½
K = 0.693 / 2
K = 0.3465 /day
Therefore, the rate of disintegration of the isotope is 0.3465 /day.
Finally, we shall determine the amount of the isotope remaining after 6 days as follow:
Original amount (N₀) = 96 g
Time (t) = 6 days
Decay constant (K) = 0.3465 /day.
Amount remaining (N) =.?
Log (N₀/N) = kt / 2.303
Log (96/N) = (0.3465 × 6) / 2.303
Log (96/N) = 2.079/2.303
Log (96/N) = 0.9027
Take the anti log of 0.9027
96/N = anti log (0.9027)
96/N = 7.99
Cross multiply
96 = N × 7.99
Divide both side by 7.99
N = 96 /7.99
N = 12.02 g
Therefore, the amount of the isotope remaining after 6 days is 12.02 g
where were atoms formed ?
Answer:
They were formed right after the "Big Bang" when our known universe originated from pure energy some billions of years ago. The energy was converted to the elementary particles (quarks, gluons, leptons etc...) from which protons and neutrons were formed. From these, atoms of different elements were produced
PLEZ HELP ANSWER. IM STUCK!
d. 3
Explanation:
because the valence electrons on O is 3
Which is a common psychological side effect of dementia?
A.optimism
B. loss of brain functionality
C. emotional distress
D.loss of coordination
Answer:
D is your Answer just did the quiz
( date on bottom when I did the quiz)
Explanation:
3 - 24 - 2021
How many grams are there in 1.18 X 1026 atoms of iridium?
which element has a grater atomic radius ?phosphorus or bismuth ?
Answer:
hello
Explanation:
bismuth has the greatest atomic radius.
To which family on the Periodic Table does this Bohr Model belong?
Answer:
As the valance shell have 7 valance electrons .
It belongs to halogen family (group 17).
what element can scratch a diomand?
Answer:
another diamond ....theres nothing else that can that I know of.
How can we determine the constants of an experiment?
Answer:
Identify the variables and constants in your experiment. In a controlled experi- ment, a is any factor that can change. Constants are all of the factors that are the same in both the experimental group and the control group.
Help me please !!!
Which of the following can be inferred from the diagram above that shows the dependence of potential Energy on the Internuclear distance between two atoms?
A)The atoms form a bond with a bond length of 25 pm
B)The atoms form a bond with a bond length of 75 pm
с)The net force between the atoms is attractive at 25 pm
D)The net force between the atoms is attractive at 75 pm
Answer:
B)The atoms form a bond with a bond length of 75 pm
Which best describes a chemical reaction that follows the law of conservation of matter?
Group of answer choices
A. The reactants have the same mass as the products.
B. The reactants have the same density as the products.
C. The products conserve all chemical properties of the reactants.
D. The products conserve all physical properties of the reactants.
PLEASE HELPP THIS IS DUEE!!!
Answer:
that's so easy but if you still need the answer i am willing to help
Explanation:
State the Periodic Law. Why is it so important in the study of chemistry?
Answer:
Summary. To summarize, the periodic table is important because it is organized to provide a great deal of information about elements and how they relate to one another in one easy-to-use reference. The table can be used to predict the properties of elements, even those that have not yet been discovered.
Convert 645 Newtons per quart to tons per liter. (The picture is a conversion table for help)
Answer:
0.067 ton/Litre.
Explanation:
645 Newtons per quart to tons per liter.
We'll begin by converting 645 Newton/quart to gram/quart (g/q). This can be obtained as:
1 N/q = 100 g/q
Therefore,
645 N/q = 645 N/q × 100 g/q / 1 N/q
645 N/q = 64500 g/q
Therefore, 645 Newton/quart is equivalent to 64500 grams per quart.
Next, we shall convert 64500 grams per quart to pounds per quart. This can be obtained as follow:
454 g/q = 1 pound/q
Therefore,
64500 g/q = 64500 g/q × 1 p/q / 454 g/p
64500 gram/quart = 142.07 pound/quart
Therefore, 64500 gram/quart is equivalent to 142.07 pound/quart.
Next, we shall convert 142.07 pound/quart to ton/quart. This can be obtained as follow:
2000 p/q = 1 ton/q
Therefore,
142.07 p/q = 142.07 pq × 1 ton/q / 2000 p/q
142.07 pound/quart = 0.071 ton/quart
Therefore, 142.07 pound/quart is equivalent to 0.071 ton/quart.
Finally, we shall convert 0.071 ton/quart to ton/litre. This can be obtained as follow:
1 ton/q = 1/1.06 ton/L
Therefore,
0.071 ton/q = 0.071 ton/q × 1/1.06 ton/L / 1 ton/q
0.071 ton/quart = 0.067 ton/Litre
Therefore, 0.071 ton/quart is 0.067 ton/Litre.
From the above illustration, 645 Newton/quart is equivalent to 0.067 ton/Litre.
Which two factors can affect a solid solute's solubility
A. Whether the particles of the solute and solvent are charged
B. Pressure acting and solute
C. Length of time spent stirring
D. Temperatures of the solvent and solute
Answer:
A and D
Explanation:
It might seem like B and D but I took the test and it's A and D.
Answer:
Whether the particles of the solute and solvent are charged
Temperatures of the solvent and solute
Explanation:
A. Whether the particles of the solute and solvent are charged
B. Pressure acting and solute
C. Length of time spent stirring
D. Temperatures of the solvent and solute
Which is responsible for an atom’s identity?
A.Protons
b.Electrons
c.Neutrons
d.Valence electrons
True or False - The central nervous system allows us to sense the environment.
Answer: no
Explanation: they tell the organs what to sense.
PLS HELP What is the name of the value located in the top right of an element?
Answer:
It's the elements atomic mass and the number of neutrons and protons in an atom.
Explanation:
Osmosis is the movement of molecules across a cell membrane. Why does this help
maintain homeostasis?
Explanation:
Osmosis helps maintain homeostasis by maintaining concentration of solvents and solutes constant inside cells.