Answer:
0.0074 moles
Explanation:
We'll have to use this forumla: PV = nRT
P = Pressure (0.724)
V = Volume in liters (0.25)
n = moles
R = 0.0821
T = temperature in kelvins (25 + 273 = 298)
Our equation will look like this:
(0.724)(.25) = n(0.0821)(298)
0.181 = 24.4658n
Divide both sides by 24.4658 to isolate n
0.181/24.4658 = 24.4658n/24.4658
n = 0.00739808
English
M.
3.x - 9
2r-7
.X + 2
18
Answer:
it will come answer 21 write
32,235 kg/1991 m3 solve in scientific notation
Answer:
jrikgni
Explanation:j
55
Round the following number to 2 significant figures:
94.5
Answer:
95
Explanation:
94.5 contains 3 significant figures so to round it to just two, we can just round the number to the nearest whole number. Remember that we round up if we have 5 and up then we would round down if we have 4 and below.
94.5 → 95
Best of Luck!
In two atoms atom 'X' looses two electrons and atom 'Y' gains two electrons to form a compound 'XY'.Name the bond formed between X and Y.With two properties of the compound.
Please help me and i will mark you as brainleist.
Answer:
The bond formed between XY is "Ionic bond"
Explanation:
The bond is ionic bond because the compound XY is formed due to the gaining and loosing of electrons
Properties of Ionic compounds:
They form crystals
They are good insulators
They have high melting and boiling points
.
.
.
Hope it helps
Someone plz help me :(
what is electron configuration?
Answer:
electron configuration is the distribution of electrons of an atom or molecule in atomic or molecular orbitals.
The main difference between strong electrolytes and weak electrolytes is....
A. their jawline.
B. how much weight they can lift.
C. how smelly of a cheese they make.
D. how much they dissociate.
Chewing food to break it down into smaller particles represents a physical change, but the charging of starch into sugars by enzymes in the digestive system represents a chemical change.Chemical or physical change?
Answer:
Chemical changeExplanation:
The charging of starch into sugars by enzymes in the digestive system shows a chemical change.[tex]\tt{ \green{P} \orange{s} \red{y} \blue{x} \pink{c} \purple{h} \green{i} e}[/tex]
How much energy is required to heat 2kg of ice from -5°c to 0°c
Explanation:
total heat = Heat required to convert 2 kg of ice to 2 kg of water at 0 °C + Heat required to convert 2 kg of water at 0 °C to 2 kg of water at 20 °C.
Heat=mhfg+mCpΔT
Here, m ( mass of ice) = 2 kg
hfg (latent heat of fusion of ice) = 334 KJ
Cp of water (specific heat) = 4.187 KJ/Kg-K
ΔT(Temperature difference) = 20 °C
Therefore, Heat required = 2 x 334 + 2 x 4.187 x (20 - 0 )
Heat reqd= 835.48 KJ
Therefore, to melt 2 kg of ice 835.48 KJ of heat is required.
What are the two differences between mass and weight?
Through _
plants move enormous quantities
of water from soil to air .
Explanation:
The water eventually is released to the atmosphere as vapor via the plant's stomata — tiny, closeable, pore-like structures on the surfaces of leaves. Overall, this uptake of water at the roots, transport of water through plant tissues, and release of vapor by leaves is known as transpiration
Through transpiration, plants move enormous quantities of water from the soil to the air.
Transpiration is the process by which plants lose water vapor through small openings called stomata in their leaves. Water is taken up by the roots from the soil and transported to the leaves through the xylem vessels. Once in the leaves, water evaporates from the surface of the cells and exits through the stomata into the surrounding air.
This continuous loss of water through transpiration creates a pulling force, known as the transpiration pull or tension, which helps to draw water upward from the roots. As water molecules evaporate from the leaves, more water is pulled up through the plant's vascular system to replace the lost water.
Transpiration not only aids in the transport of water and nutrients from the roots to the rest of the plant, but it also plays a crucial role in regulating the plant's temperature, maintaining cell turgidity, and facilitating the movement of minerals within the plant.
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in which sell duplet rule is applied, why?
Answer:
its in explanationExplanation:
the tendency for items have 2 electrons in their outermost shell by interacting with others items through electron sharing or transfer is known as duplet rule. if an atom has 2 electrons in it's outermost shell then it is called duplet rule and if a 8 electrons in it's outermost shell than it is called octet rule .
hey i got some chem for you guys
Answer:
C. Equal toExplanation:
As,
Law of reflection states that , angle of incidence is always equal to angle of reflection.
Write a scientific explanation to explain how atoms, molecules, and extended structures make up substances.
Explanation:
pure substance are made up of a bulk quantity of individual atom are molecules each pure substance in made up of one of individual atom of the same type that are connected to a form extended structure molecules of different type of atoms that are not attracted to each other eh carbon dioxide
Same type of atoms are bound to form molecules, these molecules are joined to form larger pure compound.
What do you mean by atom and molecule ?Atoms are the smallest and basic units of matter which has three subatomic particles such as positively charged protons, neutral Neutrons form nucleus.
A negatively charged electron which surround the nucleus of the atom.
The nucleus does not change during chemical reactions, only in nuclear reactions it will change.
In nucleus equal number of protons and neutrons, atomic number is the number of protons and atomic mass is made of the sum of protons and neutrons.
Smaller electrons orbit the nucleus participate in chemical reactions .
A molecule is defined as two or more atoms bonded together by different bonds like ionic, covalent, electrostatic, coordinate bonds.
Examples of molecules includes carbon dioxide, water, ammonia, glucose etc.
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Label each of the following 15 samples of matter as one of the following:
Explain how you can obtain hydrated sodium sulphate crystals from an aqueous solution of sodium sulphate
Answer:
If you left your aqueous sodium sulfite solution open on the side, atmospheric oxygen would cause the chemical change, the water would hydrate the new compound and the slow evaporation of water would give you lovely large crystals of Na2SO4 without you having to do anything!
Answer:
If you left your aqueous sodium sulfite solution open on the side, atmospheric oxygen would cause the chemical change, the water would hydrate the new compound and the slow evaporation of water would give you lovely large crystals of Na2SO4 without you having to do anything!
Which hypothesis is most supported by astronomers?
The universe is currently expanding and will continue to expand.
Stars could burn out, causing the universe to become dark and cold.
Gravity could pull galaxies back together, causing a reverse of the big bang.
Dark energy will pull the universe together to form a massive black hole.
Answer:
Once I read a NASA post where they were saying that the universe keeps expanding as matter keeps forming and cooling down thus adding to the size of the universe so keeping this in mind, the best answer choice is, option A. The universe is currently expanding and will continue to expand.
The hypothesis which is most supported by astronomers is that universe
is currently expanding and will continue to expand.
Who are Astronomers?They are scientists which study planets, stars, and other celestial bodies.
They have strong beliefs on Big bang theory.
The theory states that the Universe was formed as a result of a big bang in
which one point began to expand . This is why option A is the most
appropriate.
Read more about Astronomers here https://brainly.com/question/10826203
Which of these is about the same size and mass as a CARBON proton?
A.
electron
B.
neutron
Neutrons and protons are almost exactly the same size
Explanation:
(a neutron has about 1/10th of one percent more mass). ... Carbon has 6 protons, so its atomic number is 6; oxygen has 8 protons, so its atomic number is 8. Uranium has 92 protons, so its atomic number is 92!
Answer:
neutrons
Explanation:
it’s for Acellus
A hydrogen electron is elevated from level 1 to level 2. Another electron is elevated from level 2 to level
4. The transition requiring the greatest energy change is
DONE
Intro
Answer
level 2 to 4
Explanation:
i guessed cause im just that cool
Which of the following is NOT an alternative source of energy?
A: Water
B: Wind
C: Sun
D: Plants
Hello guys can you help me on this.
Answer:
1.Sulfur dioxide and nitrogen oxide
2.a)it forms carbonic acid
b)
3.the community can use renewable energy like solar and wind power cause they produce less pollution
A _______ is a substance used during electrolysis that splits apart and is attracted to an oppositely charged electrode
Answer:
electrolyte
Explanation:
Why the volume of a gas is not measured immediately after it is collected?
Answer:
Collecting gas over waterWhen collecting oxygen gas and calculating its partial pressure by displacing water from an inverted bottle, the presence of water vapor in the collecting bottle must be accounted for; this is easily accomplished using Dalton’s Law of Partial Pressures.
Pb(NO3)2 + ? = PbCl2 +?
Answer:
HCL, H2
Explanation:
Assuming this is a Redox reaction, we know that metal + acid = salt + hydrogen therefore we can say it is HCL and H2
What are the periods and epochs of the Cenozoic era?
Please help!
Answer:
The Cenozoic Era is generally divided into three periods: the Paleogene (66 million to 23 million years ago), the Neogene (23 million to 2.6 million years ago), and the Quaternary (2.6 million years ago to the present); however, the era has been traditionally divided into the Tertiary and Quaternary periods.
Heisenberg's uncertainty principle stats that's isn't possible to know the exact momentum and _______ of a particle simultaneously. In terms of atomic structure, this means that we can't determine fixed ________ for electrons but can only determine the _________ of finding an electron in a given region of space.
71. The density of osmium (the densest metal) is 22.57 g/cm². If a
1.00-kg rectangular block of osmium has two dimensions of
4.00 cm x 4.00 cm, calculate the third dimension of the block.
Answer:
y = 2.77 cm
Answer: The third dimension is 2.77 cm
during the interconversion of state of matter, mass undergoes and change? true or false
True.
The Mass Undergoes change only in ( Solid state to liquid state ) Ice Cube to Water .
Mass changes from mg to litre.
[tex]\huge\mathfrak\red{hope \: it \: helps}[/tex]
Plz help!!!!
11. Jack placed his new birthday helium balloon into the freezer. Will the balloon expand or shrink?
Describe what would happen to the helium gas particles. Be sure to include information about the gas
particle movement, volume (space between particles), and pressure.
Answer:
The balloon will shrink bcuz the average kinetic energy of the helium gas particles in the balloon decreases when the temp decreases. This makes the molecules move more slowly and have less frequent and weaker collisions with the inside wall of the balloon. The pressure will also decrease bcuz air pressure is the total force per unit area
if you are asked to help the laboratory assistant in separating the mixture which method will you see?
Answer:
use secondary data. the normal method to use