Choose all of the examples that show a chemical change.
A) A woodpecker digs in the bark.
B) A dead tree rots on the ground.
C) A forest fire burns a lot of trees.
D) A farmer is cutting logs with an axe.
E) A tree drops rainwater from its leaves.
Answer:
B and C
Explanation:
Answer:
B) A dead tree rots on the ground.
C) A forest fire burns a lot of trees.
Explanation:
It cannot return the the state it was in before or have the same composition it had before.
The paths that planets follow around the sun are called ____ , and they are shaped like an ellipse.
The paths that planets follow around the sun are called as orbit, and they are shaped like an ellipse.
What is orbit ?The orbits of the planets around the sun are elliptical. Kepler, an astronomer, provided a clear definition of these orbits. The three rules he created are referred to as Kepler's laws of planetary motion. It says that every planet does an orbit around the sun.
The plane of Earth's orbit around the sun serves as the definition of the ecliptic. The primary planets of our solar system, their moons, some asteroids, and their orbits all roughly follow this plane.
An orbit is a curved path taken by an object, such as a planet's path around a star, a natural satellite's path around a planet, or a man-made satellite's path around a planet, moon, or asteroid.
Thus, the paths that planets follow around the sun are called as orbit.
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please help fast thank yuo
Answer:
what is your question tell may i can help you
Answer:
decrease as we go down a group I know ionisation energy increases from left to right across the periodic table
True or false: The
louder you yell into a
megaphone in space,
the more likely it is for
the sound waves to
travel.
Answer:
True
Explanation:
This is known as a lapse rate. When you shout something to someone across the lake, the sound waves near the surface end up moving faster than the sound waves higher up. Since the speed is greatest near the ground, sound waves bend upward, causing the audio to be just out of ears reach.
NO LINKS
Select the correct answer.
In which situation is chemical energy being converted to another form of energy?
A.
a lamp plugged into the electric grid
B.
a fluttering flag
C.
a floating wooden log
D.
a burning candle
Pls help if you only know the correct answer! Thanks! :)
18. the blank should be "[tex]CO_{2}[/tex]"
19. the question seems to be answered.
20. [tex]CH_{3}[/tex]
Identify the subatomic particles in strontium-82 and rubidium-82. Then, explain what type of nuclear decay is most likely to convert strontium-82 to rubidium-82.
We can convert strontium-82 to rubidium-82 by positron emission.
The three main fundamental subatomic particles in an atom are;
ProtonsNeutronsElectronsIn a neutral atom, the number of protons is always equal to the number of electrons.
In strontium-82, there are 44 neutrons, 38 electrons and 38 protons. In rubidium-82, there are 45 neutrons, 37 electrons and 37 protons. We can convert strontium-82 to rubidium-82 by positron emission.
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which particle diagram represents a sample of oxygen gas at stp
The diagram in image (4) in the image attached represents a sample of oxygen gas at stp.
Oxygen is a diatomic molecule, a diatomic molecule is a molecule that consists of only two atoms of the same element. In this case, the oxygen molecule consists of two oxygen atoms.
If we look at the diagram in the image attached very well, we will discover that the image in diagram (4) shows a molecule composed of two atoms of the same element and this fits exactly into the description of the oxygen molecule.
Learn more about diatomic molecules:
Particle diagram 4 represents the particles of oxygen at standard temperature and pressure.
A model of molecular (or diatomic) oxygen, which is made up of two oxygen atoms attached to each other through a covalent bond.
Dioxygen, also known as oxygen, is a naturally occurring molecule made up of two oxygen atoms that attach to each other with a strong covalent bond to form oxygen (dioxygen). Oxygen is sp3-hybridized, i.e. it has 4 sp3 hybrids. One of these hybrid orbitals overlaps with the s orbitals of hydrogen to create the O-h sigma bonds.
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The diagram in question is attached below.
electric current is passed through water, it decomposes inti hydrogen and oxygen. write full balanced chemical equation for the reaction
Answer:
2H2O ------------------] 2H2 + O2
PLEASE HELP
2.How many atoms are in 3.35 moles of Aluminum?
3.How many moles of CO2 gas are in a 101.25 L container filled with CO2 gas?
4.What is the mass of 13.7 moles of N2 gas?
Answer:
2: 2.02 x 1024 atoms
3: 4.5201 atoms
4: 384 g/mol
Explanation: I'm in your class
what activity occurs in the process of photosynthesis
Answer:
Photosynthesis is the process in which light energy is converted into chemical energy in the form of sugars. In a process powered by light energy, glucose (and other sugars) molecules are created from water and carbon dioxide, while oxygen is released as a by-product.Explanation:
i'm mexican
calculate the volume in dm3 occupied by 26.4 g of carbon dioxide
[tex]\\ \sf\longmapsto Density=\dfrac{Mass}{Volume}[/tex]
[tex]\\ \sf\longmapsto Volume=\dfrac{Mass}{Density}[/tex]
[tex]\\ \sf\longmapsto Volume=\dfrac{0.0264}{1564}[/tex]
[tex]\\ \sf\longmapsto Volume=1.687m^3=1.69m^3[/tex]
1m^3=1000dm^3[tex]\\ \sf\longmapsto Volume=1.69(1000)=1690dm^3[/tex]
Use the chemical equation to complete the activity.
4Fe + 3O2 → 2Fe2O3
Iron (Fe) reacts with oxygen (O2) to form iron oxide. A scientist adds 15.4 grams of Fe to 3.6 grams of O2 to start the reaction. All of the iron and oxygen react to form iron oxide. Explain in detail how you can determine how many grams of iron oxide will be produced.
Use the law of conservation of matter in the explanation.
Answer:
14.54 g Fe2O3
Explanation:
The first step would be to balance the equation but since it's already balanced we don't have to worry about that.
Through the balanced equation, you can find the stoichiometry of the reaction, that is:
4 moles of Fe, react with 3 moles of O2, to produce 2 moles of Fe2O3
Chemistry (accurately stoichiometry) is all about ratios and proportions. The balanced equations gives you the standard ratio by which moles are produced.
So the next step (shown in the paper), is to convert the grams that are giving you in Moles, and you do this by dividing the number of grams given by the molar mass of the substance. The molar mass is the number of grams by which you can find exactly 6.022x10²³ molecules (one mole) of one specific substance.
15.4 g of Fe= 0.28 mol Fe
3.6 g of O2= 0.11 mol O2
Now that you have the quantity of moles, what you need to do is to look for the limitant reactant.
In a balanced equation, the number of moles in the reactants are the rules and they're gonna react completely with each other. If you want x quatity of reactants to react completely, then you will have to respect the proportion to the ratio given in the balanced equation.
But you will rarely follow the proportion so there will usually be a reactant that's gonna be limiting the reaction and one that is in excess. And how do you find this? Well, the easiest way to do it is:
Dividing the number of moles obtained by x element the coefficients of that element in the balanced equation. The one that has the smallest ratio, is the limitant reactants.Since the limitant reactant is gonna be limiting the reaction, all the stoichiometric procedures should be calculated through it, and in this case, the limitant reactant is O2.
But then how to establish the stoichiometric rule to find the number of Iron oxide (III) that's being produced?
Look back to the stoichiometry of the reaction:
To produce 2 moles of Fe2O3, you need 3 moles of O2.
But you have 0.11 mol O2.
Then establish a factor of conversion (shown in the picture)
The result is 0.07 mol of Fe2O3, but you need the answer in grams so you find the molar mass of Fe2O3 and then multiply it by the number of moles (0.07)
The answer is 14.54 g of Fe2O3
CHEMISTRY IS ALL ABOUT PROPORTIONS :D
what is the oxidation number of oxygen in most compounds
Answer:
2-
Explanation:
Oxygen always act with an oxidation number of 2- unless we're talking of peroxide such as H2O2, where oxygen acts with an oxidation number of 1-
10. Would it be possible for an earthquake at this same location to be felt where you live? Why or why not ?
Answer:
yes if big no if weak
Explanation:
According to new research, a large earthquake can not only cause other quakes, but also large ones on the opposite side of the Earth.
What is an earthquake and how it is caused?An earthquake is a sudden movement of rock materials beneath the earth's surface that causes a weak to violent shaking of the ground. The earthquakes are caused by tectonic plate boundaries.
Every day, earthquakes occur all over the world, along both tectonic plate edges and interiors. Earthquakes happen along faults, which are fractures in the rock that allow the blocks to move relative to one another.
Earthquakes are typically caused by underground rock suddenly breaking and rapid movement along a fault. The seismic waves that cause the ground to shake are caused by this sudden release of energy.
A large earthquake can not only cause other quakes, but also large ones on the opposite side of the Earth, according to new research.
Thus, it is possible for an earthquake at this same location to be basically felt where you live.
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A scientist tested a series of solutions to determine their pH, and recorded the results in this table.
Substance pH
A 9
B 12
C 11
D 14
According to this data, which solution would be most effective at neutralizing a strong acid?
Substance A
Substance B
Substance C
Substance D
Answer:d
Explanation:
1. Which of the following statements about the properties of elements related to an
atomic emission spectrum are true? Select all that apply. (3 are correct)
The emission spectrum of an atom consists of limited lines that are unique to a given element.
According to the Bohr model of the atom, energy is absorbed or emitted when an atom moves from one energy level to another. Since energy is quantized, the spectrum of atoms often consists of single lines.
Hence, the true statement about atomic spectrum is that; "the light that an element emits is made up of a limited number of narrow lines that produce a unique pattern or atomic emissions spectrum for that element."
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Most stars are part of the main sequence of stars in the HR diagram
Question 2 options:
True
False
how much water will you need to add to your working solution to get to a 100 ml total volume of a 0.03m nacl solution?
Answer:
The solution is made by adding 4.38 g NaCl to a 250-mL volumetric flask. About 100 mL of water are added and when all the NaCl dissolves water is added up ...
Here is Beck's address:
12 Riverdale Lane, Apartment A
San Jose, California
USA
Imagine each of the five parts of Beck's address represents Earth, the Milky Way, the moon, the solar system, or the universe, based on their sizes. Which of the
following parts of Beck's address would represent the solar system?
O California
O 12 Riverdale Lane
San Jose
O USA
Answer:
The answer is San Jose
arrange the bromine-containing compounds cabr2, br2, asbr3, cbr4 in order of increasing normal boiling point.
Answer:
Br2, CBr4, AsBr3, CaBr2. this is the increasing order of boiling point
The arrangement of given compound in the increasing order of normal boiling point is Br₂ < CBr₄ < AsBr₃ < CaBr₂.
What is normal boiling point?Norma boiling point of any liquid is that point where the vapor pressure is equal to the standard sea level atmospheric pressure.
And boiling point is directly proportional to the strength of bond which is present between the atoms of any compound.
As we know that ionic bond is the strongest bond and in CaBr₂ ionic bond is present so the boiling point of this compound will be highest.In AsBr₃, bromine is more electronegative than arsenic and arsenic also have one lone pair on it so some dipole moment develope in it and then this compound will have boiling point less than CaBr₂.CBr₄ is a covalent compound as in this compound bromine is present which is more electronegative but overall dipole moment of this compound is zero.Br₂ is also a covalent molecule and it has no dipole moment in it and have minimun boiling point among all compounds.So, correct order will be Br₂ < CBr₄ < AsBr₃ < CaBr₂.
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Look at the diagram. Which shows the correct arrangement of electrons in a hydrogen chloride molecule?
Answer:
D............................
There are two types of chemical compound one is covalent compound and another is ionic compound, covalent compound formed by sharing of electron and ionic compound formed by complete transfer of electron. The correct representation is option D.
What is chemical Compound?Chemical Compound is a combination of molecule, Molecule forms by combination of element and element forms by combination of atoms in fixed proportion.
Covalent bond is present in molecule HCl. Hydrogen has 1 electron in its outermost shell. Chlorine has 7 electrons in its valence shell. So one one electron from each element is shared between them to form a covalent bond.
Therefore, the correct representation of arrangement of electrons in a hydrogen chloride molecule is option D.
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A sample of nitrogen gas at STP has a volume of 65.8 L. What is the mass of the gas?
A)
82.3 g
B) 41.18
2.94 g
07
0.210 g
E
0.1058
Answer:
B
Explanation:
Find the percent composition of OXYGEN in Manganese (III) nitrate, Mn(NO3)3.
Answer:
Mn(NO3)3 Molar mass = (54.93) + (3 x 14) + (9 x 16) = 240.93g/mol
Total number of Oxygen atoms in formula = 9
Total mass of oxygen atoms theoretically in the formula = 9x16 = 144g/mol
Oxygen's percentage composition:
(144/240.93) x 100 = 59.7% of the compound is oxygen
How many moles of AgCl can form from 6.5 moles of Ag and abundant HCl in the equation: 2Ag + 2HCl -> 2AgCl + H2
6.5 moles of AgCl can be formed from 6.5 moles of Ag.
STOICHIOMETRY:
According to this question, silver reacts with hydrochloric acid to form silver chloride and hydrogen gas as follows:
2Ag + 2HCl → 2AgCl + H2
Based on this balanced equation, 2 moles of silver (Ag) produces 2 moles of silver chloride (AgCl).
This means that 6.5 moles of Ag will produce (6.5 × 2)/2 = 6.5 moles of AgCl.
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how many moles of oxygen would you need to produce 4 moles of aluminum oxide? 4 Al + 3 O2 ----> 2 Al2O3
Answer:
6 moles
Explanation:
3 moles of O2 produce 2 moles of Al2O3 so in order to produce 4 moles pf AL2O3 you need 4 x 3 /2 moles of O.
Which of the following is an oxidation-reduction reaction? Fe2O3 3CO Right arrow. 2Fe 3CO2 CuSO4 2NaOH Right arrow. Cu(OH)2 Na2SO4 2NaOH H2CO3 Right arrow. Na2CO3 2NaOH Pb(NO3)2 Na2SO4 Right arrow. 2NaNO3 PbSO4.
The reaction, Fe2O3 + 3CO------> 2Fe + 3CO2 is an oxidation-reduction reaction.
An oxidation-reduction reaction is a reaction in which there is a change in oxidation number from left to right in the reaction. This is because, a specie is oxidized and another specie is reduced.
In the reaction; Fe2O3 + 3CO------> 2Fe + 3CO2, we can see that the oxidation number of iron decreased from +3 on the left hand side to zero on the right hand side. The oxidation number of carbon was increased from + 2 to +4.
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Answer:
A
Explanation:
EDGE2022
True or False: A food chain is the feeding relationships among all the organisms in an
ecosystem.
Answer:
False.
Explanation:
A food web is the feeding relationships among all the organisms in an
ecosystem.
.・。.・゜✭・have a nice day・✫・゜・。.
what does the heisenberg uncertainty principle state
Answer: It states that there is a fundamental limit to what one can know about a quantum system.
Explanation:
noble gases are used in many situations where a safe and constant environment must be maintained. for example, helium is used to provide a protective atmosphere for making fiber optics and semiconductors. argon is used to fill incandescent and flourescent light bulbs to prevent oxygen from corroding the hot filament. why are noble gases used in these situations?
Answer:
Noble gases have a complete valence electron shell making them stable and nonreactive.
Explanation: