Answer:
Objects that can emit light energy by themselves are known as luminous objects. Objects that cannot emit light energy by themselves are known as non-luminous objects.
Explanation:
Explanation:
Luminous objects:- The objects that can emit light energy by themselves are known as luminous objects.
Objects like the sun that give out or emit light of their own are luminous objects.
Other examples of luminous bodies are Electric bulb, torch etc.
Non-luminous objects:- the objects that can not emit light energy by themselves are known as Non- luminous objects.
Objects like the moon that do not give out or emit light of their own are Non- luminous objects.
Moon is an example of a non-luminous object as we can see the moon because it reflects light from the sun.
Other examples of Non luminous bodies are pen, pencil, chair, wood etc.
Luminosity – It is defined as the luminous intensity in a particular direction; or we can say it is the apparent brightness of an image.
The brightness of a star is defined as the total energy radiated in unit time. It is related to the surface area (A) and the effective temperature (TT) ( the temperature of a black body having the same radius as the star and radiating the same amount of energy per unit area in one second ) by a form of Stefan’s law, here is given by
⇒L=AσT4⇒L=AσT4
where
σ is the Stefan’s constant and L is the luminosity.
Note:
The laptop screen, mobile screen you are looking at right now is luminous but the page of your book is a non-luminous object, which is why you need a light on to read it.
highlighters are like
pepper
salt
sugar
water
Answer:
wait what? is this a homework question?
Calculate the moles in 3x10^22molecules of water
Answer:
It is 0.05 moles of water
Explanation:
From avogadro's number:
[tex]{ \sf{6.02 \times {10}^{23} \: mole cules= 1 \: mole }} \\ { \sf{3 \times {10}^{22} \: molecules = ( \frac{3 \times {10}^{22} }{6.02 \times {10}^{23} }) \: moles }} \\ \\ { \sf{ = 0.05 \: moles}}[/tex]
Answer:
[tex]\boxed {\boxed {\sf 0.05 \ mol \ H_2O}}[/tex]
Explanation:
We are asked to calculate the number of moles of water, given the molecules of water.
We will convert moles to molecules using Avogadro's Number or 6.022 × 10²³. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance. In this case, the particles are molecules of water or H₂O.
We will convert using dimensional analysis, so we must set up a ratio using Avogadro's Number.
[tex]\frac {6.022 \times 10^{23} \ molecules \ H_2O} { 1 \ mol \ H_2O}[/tex]
We are converting 3 × 10²² molecules of water to moles, so we must multiply the ratio by this value.
[tex]3 \times 10^{22} \ molecules \ H_2O*\frac {6.022 \times 10^{23} \ molecules \ H_2O} { 1 \ mol \ H_2O}[/tex]
Flip the ratio so the units of molecules of water cancel.
[tex]3 \times 10^{22} \ molecules \ H_2O*\frac{ 1 \ mol \ H_2O} {6.022 \times 10^{23} \ molecules \ H_2O}[/tex]
[tex]3 \times 10^{22} *\frac{ 1 \ mol \ H_2O} {6.022 \times 10^{23}}[/tex]
[tex]\frac {3 \times 10^{22}} {6.022 \times 10^{23}} \ mol \ H_2O[/tex]
[tex]0.04981733643 \ mol \ H_2O[/tex]
The original value of molecules of water ( 3 × 10²² ) has 1 significant figure, so our answer must have the same number of sig figs. For our answer that is the hundredth place. The 9 in the thousandth place tells us to round the 4 in the hundredth place up to a 5.
[tex]0.05 \ mol \ H_2O[/tex]
3×10²² molecules of water are equal to 0.05 moles of water.
How many GRAMS of phosphorus are present in 2.75 moles of phosphorus pentachloride ?
Answer:
molecular weight of Phosphorus Pentachloride or grams The molecular formula for Phosphorus Pentachloride is PCl5. The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles Phosphorus Pentachloride, or 208.238761 grams.
Explanation:
may this answer is helpful for you
electrolysis of aqueous copper(2) sulfate half ionic equation
Answer:
Copper is less reactive than hydrogen, so copper (Cu) is produced at the negative electrode. The half equation is: Cu2+ + 2e- → Cu
The hydroxide ion is more reactive than the sulphate ion, therefore this forms water (H2O) and oxygen at the positive electrode.
What is the signifcence of H, 2H, 3 H, H2, 2 He, Na,
Snaco, ouco, CO, 460?
H=hydrogen,H2=hydrogen atoms,
Which of the following statements correctly explains why the excretory system is different from the digestive system? (1 point)
The excretory system is different from the digestive system because it removes waste from the body by filtering water, which
includes mostly the by-products of metabolism
The excretory system is different from the digestive system because it removes waste from the body by filtering urine, which
includes mostly the by-products of metabolism
The excretory system is different from the digestive system because it removes waste from the body by filtering food, which
includes mostly the by-products of metabolism, filtering food
The excretory system is different from the digestive system because it removes waste from the body by filtering blood, which
includes mostly the by-products of metabolism,
The body is composed of several systems. Each system involves various organs and associated structures.
The correct answer is "The excretory system is different from the digestive system because it removes waste from the body by filtering food, which
includes mostly the by-products of metabolism."
The digestive system is mostly concerned with the breakdown of food and its subsequent absorption in the body. Several organs are responsible for this from the mouth to the small intestine.
The excretory system filters removes wastes from the body by filtering food substances which includes mostly the by-products of metabolism.
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Which sentence best describes how matter moves through an ecosystem?
A.
Matter only moves from producers to decomposers.
B.
Matter only moves from consumers to producers.
C.
Matter is made by producers and is destroyed when eaten.
D.
Matter is continually cycled through an ecosystem.
Answer: D
Explanation: A healthy ecosystem is capable of exisitng based on the matter within that ecosystem. Energy is often supplied externally (e.g., the sun, geothermal, etc.) and is stored by the ecosystem in the form of chemical bonds made between the elements. Plants utilize matter (minerals, carbon dioxide, water) within the ecosystem (plus whatever is delivered via asteroid or candy wrappers). Animals depend on the plants for both energy and matter that is transformed into the compunds needed for their existence. Decomposers act to reduce complex matter (plants and animals) back into more basic compounds that then reenter the ecosystem as raw material for he next set of plants, animals, humans, and aliens.
what are adipoyl chloride used for or uses?
Answer:
Explanation:
It is a colorless liquid. It reacts with water to give adipic acid. It is prepared by treatment of adipic acid with thionyl chloride.
Adipoyl Chloride can be used in the synthesis of nylon. Also it is used in the synthesis of chiral polymer for membrane application.
Can someone help me?
Which element would have the lowest electronegativity?
an element with a large number of valence electrons and a small atomic radius
an element with a large number of valence electrons and a large atomic radius
an element with a small number of valence electrons and a large atomic radius
an element with a small number of valence electrons and a small atomic radius
Answer:
an element with a large number of valence electrons and a large atomic radius
Explanation:
Electronegativity means a tedency when an atom attracts bonding electrons in a covalent bond situation.
» If an atom has many valency electrons [ empty orbitals in outermost shell ], it has difficulty in attracting electrons hence electronegativity low.
» If an atom is large, its nuclear attraction force of incoming electrons is low hence low electronegativity.
[tex].[/tex]
The element that would have the lowest electronegativity is an element with a small number of valence electrons and a large atomic radius.
Both electronegativity and atomic radius are periodic trends. Electronegativity increases across the period while atomic radius decreases across a period.
An element that has a small number of valence electrons and a large atomic radius will most likely be a metal hence it will have the lowest electronegativity.
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how many times larger is 45000 than 0.0045?
Answer:
10,000,000
Explanation:
45000÷0.0044
=10,000,000
Answer:
10,000,000 times larger.
Explanation:
Multiply 0.0045 by 10,000,000 to get 45000. Or, Divide 45000 by 0.0045 to get 10,000,000.
Give reason
1) The efficiency of a practical machine is less that 100%.
1) The efficiency of a machine can be increased by using lubricants in the movable parts.
Explanation:
The efficiency of a practicle machine is less than 100% because some of the applied force is wasted due to oovercoming friction.The efficiency of a machine can be increased by using lubricants in the movable parts because lubricants helps to reduce friction.I hope it helped U
stay safe stay happy
Which of these is a reason why nuclear power is important?
4.4.2 nuclear power
Answer:
Fossil fuels will run out soonHow old is a piece of cotton cloth if the half-life of carbon-14 is 5,730 years, and the carbon-14 composition of the cloth is 22 percent that of living plants?
Answer:5600 years
Explanation:
the amount of time it takes for the quantity to lose 50% (Half life) of its value. The half-life of carbon-14 is about 5600 years. Thus, after 5600 years, a piece of cotton cloth will contain half the carbon-14 that was in the original cotton plant.
What are two factors that can change the rate of a chemical?
Answer:
the surface area of a solid reactant.
temperature.
presence/absence of a catalyst.
Which statement best describes why an element's atomic number is different from its atomic mass?
A. The atomic number represents the number of electrons, while the atomic mass represents the total mass of the protons and neutrons.
B. The atomic number represents the number of protons, neutrons, and electrons, while the atomic mass represents the total mass of the protons, neutrons, and electrons.
C. The atomic number represents the number of protons, while the atomic mass represents the total mass of the protons, neutrons, and electrons.
D. The atomic number represents the number of protons, while the atomic mass represents the total mass of the protons and electrons.
Answer: C
Explanation: The atomic number is fixed by the number of protons. An element will have an exact number of protons. The neutrons can vary, and they are the reason elements have isotopes (all the same number of protons, but some have differing numbers of neutrons). Electrons are too small to be counted in the atomic weight figures.
If a lab fire erupts, immediately
A) notify parent or guardian
B) run for fire extinguisher
C) throw water on fire
D) open window
Answer:
B
Explanation:
best way to put off the fire
Answer:
b
Explanation:
by the time you tell some one the fire could have spread and throwing water could spread the fire and opening the window adds fuel to the fire so it can burn hotter
Which of these answers describes a scientific law?
(Pls)
Answer:
big ablsolty long pp
Explanation:
dong
Can someone PLEASE help me with this im struggling bad
Answer:
4.5+2.34= 6.844.5-5 =-0.56.00+3.411= 9.4113.4×2.32 = 7.8887.77/2.3= 3.377. 1200×23.4=28080
9. = 78.512
10. =341.199
11= 7.45
12 =65.0023
13.=3400210.34
Explanation:
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hope it is helpful
Which of the following is a scientific question you could ask about shoes?
A. Are modern sandals similar to sandals from the 1960s?
B. What shoes will be popular next summer?
C. What is my favorite shoe color?
D. Are there any running shoes that help people run faster?
Answer:
D. Are there any running shoes that help people run faster?
Explanation:
because it's the question that more seems scientific.
i hope this helps
Helppppp….. is this right?
Answer:
Yes, it is correct.
Explanation:
400 cm = 4 m
40 m = 40 m
0.4 km = 400m
Therefore, 400 cm < 40 m < 0.4 km
Answer:
Explanation:
400 centimeter....... smallest
0.4 kilometer .............. middlest
40 meter..................... greatest
(a) Explain why ammonia has a low boiling point
Explanation: Ammonia has pretty strong intermolecular forces because it can form hydrogen bonds, however it can't form as many hydrogen bonds per molecule as water and so its boiling point and melting point are lower.
As ammonia has less intermolecular force of attraction, it have usually low boiling point.
What is hydrogen bonding?Hydrogen bonding is not a covalent bond to a hydrogen atom, but rather a type of dipole-dipole attraction between molecules.
The attractive force between a hydrogen atom covalently bonded to a very electronegative atom such as an N, O, or F atom and another very electronegative atom causes it.
When a hydrogen atom bonded to an electronegative atom approaches another electronegative atom, strong intermolecular forces are created.
Simple molecules include hydrogen, ammonia, methane, and pure water. All of them have strong covalent bonds among both their atoms but much weaker intermolecular forces.
When one of these substances melts or boils, the weak intermolecular forces, not the strong covalent bonds, break.
Thus, ammonia usually have low boiling point.
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Which equation represents a decomposition reaction?
O 4P +502 → 2P205
O H2SO4 + 2NaOH → Na2SO4 + 2H2O
O 2C8H18 + 2502 → 16CO2 + 18H2O
O 6NaNO3 → 6NaNO2 + 302
There are various type of chemical reactions in chemistry like combination reaction , displacement reaction. One of these is the decomposition reaction. The correct option is option D.
What is decomposition reaction?Decomposition reaction is the one in which molecules breaks down in its constituent in presence of energy. Energy can be in any form, it can be light energy , heat energy.
Decomposition of water is done by providing electricity and the reaction is called electrolysis. Lysis means to break. To give decomposition reaction molecule must have more than one element.
The fourth reaction describe a decomposition reaction (NaNO3 decomposed to become NaNO2 and O2). First and third reaction are considered combustion reaction (reacting with oxygen). Second reaction is acid-base reaction.
Therefore, the correct option is option D.
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6. When conducting experiments, scientists use
to help guide their processes.
When conducting research, scientists use the scientific method to collect measurable, empirical evidence in an experiment related to a hypothesis (often in the form of an if/then statement), the results aiming to support or contradict a theory.
Hope this helps you!
what is force ?write its effects.
Answer:A force is a push or pull upon an object resulting from the object's interaction with another object.
A force acting on an object causes the object to change its shape or size, to start moving, to stop moving, to accelerate or decelerate
What is the equation used to calculate the density of a material?
Answer:
density = (mass) divided by (volume)
or just D = M/V
A gas has a volume of 4.25 m3 at a temperature of 95.0°C and a pressure of 1.05 atm. What temperature will the gas have at a pressure of 1.58 atm and a volume of 2.46 m3
Answer:
[tex]\boxed {\boxed {\sf 82.7 \textdegree C}}[/tex]
Explanation:
We are asked to find the temperature of a gas given a change in pressure and volume. We will use the Combined Gas Law, which combines 3 gas laws: Boyle's, Charles's, and Gay-Lussac's.
[tex]\frac {P_1V_1}{T_1}=\frac{P_2V_2}{T_2}[/tex]
Initially, the gas has a pressure of 1.05 atmospheres, a volume of 4.25 cubic meters, and a temperature of 95.0 degrees Celsius.
[tex]\frac {1.05 \ atm * 4.25 \ m^3}{95.0 \textdegree C}= \frac{P_2V_2}{T_2}[/tex]
Then, the pressure increases to 1.58 atmospheres and the volume decreases to 2.46 cubic meters.
[tex]\frac {1.05 \ atm * 4.25 \ m^3}{95.0 \textdegree C}= \frac{1.58 \ atm *2.46 \ m^3}{T_2}[/tex]
We are solving for the new temperature, so we must isolate the variable T₂. Cross multiply. Multiply the first numerator by the second denominator, then multiply the first denominator by the second numerator.
[tex](1.05 \ atm * 4.25 \ m^3) * T_2 = (95.0 \textdegree C)*(1.58 \ atm * 2.46 \ m^3)[/tex]
Now the variable is being multiplied by (1.05 atm * 4.25 m³). The inverse operation of multiplication is division, so we divide both sides by this value.
[tex]\frac {(1.05 \ atm * 4.25 \ m^3) * T_2}{(1.05 \ atm * 4.25 \ m^3)} = \frac{(95.0 \textdegree C)*(1.58 \ atm * 2.46 \ m^3)}{(1.05 \ atm * 4.25 \ m^3)}[/tex]
[tex]T_2=\frac{(95.0 \textdegree C)*(1.58 \ atm * 2.46 \ m^3)}{(1.05 \ atm * 4.25 \ m^3)}[/tex]
The units of atmospheres and cubic meters cancel.
[tex]T_2=\frac{(95.0 \textdegree C)*(1.58* 2.46 )}{(1.05 * 4.25 )}[/tex]
Solve inside the parentheses.
[tex]T_2= \frac{(95.0 \textdegree C)*3.8868}{4.4625}[/tex]
[tex]T_2= \frac{369.246}{4.4625} \textdegree C}[/tex]
[tex]T_2 = 82.74420168 \textdegree C[/tex]
The original values of volume, temperature, and pressure all have 3 significant figures, so our answer must have the same. For the number we calculated, that is the tenths place. The 4 in the hundredth place to the right tells us to leave the 7 in the tenths place.
[tex]T_2 \approx 82.7 \textdegree C[/tex]
The temperature is approximately 82.7 degrees Celsius.
What is the Color of trioxonitrate
Answer:
And the ans is yellowish
Based on the definition given,
which sentence correctly uses
the word compare?
A. Compare the total amount of rainfall in
California for the year 2011.
B. Compare the similarities of the climate
in Ireland with the climate in Greenland.
C. Compare the best way to prepare to
take a standardized test.
Answer: B. Compare the similarities of the climate in Ireland with the climate in Greenland.
We should Compare the similarities of the climate in Ireland with the climate in Greenland.
a plant dies if it's phloem tissue is removed .why?
So if I was shrunken into a tiny person what would you do to me like would you take care of me would you crush me with your bare feet or something
Explanation:
It is really bad when you are in some kind of problems and you don't have anybody to help you out. You do not even know where you will meet a person you treated good or bad. We have to treat every human equally,no matter the outcome.
So in my opinion, I would take care of you.