Answer:
Aristotal
His view of atoms was very different from how we think of atoms now but he was technically the first person to propose the basic idea of atoms.
NO LINKSSS PLEASE
When preparing a saturated solution of sodium nitrate in water, which of the following actions would speed up the rate of solution?
Select one:
a. Stirring the solution.
b. Evaporating the solvent.
c. Filtering the solution.
d. Cooling the solvent.
Answer:
a. Stirring the solution.
At what temperature does ice melt at 101kPa?
Answer:
Explanation: I also have a question if anyone can help in chem please
what is the gram formula mass of NazC03
Answer:
84,007 g/mol
Explanation:
Molar mass of NazCO3 which is Sodium Bicarbonate (NaHCO₃) is 84,007 g/mol
What statement most likely describes the effects of this movement at each location?
Location A creates a volcano; Location B uplifts and forms a mountain
Location A uplifts and forms a mountain; Location B creates a volcano
Location A creates a gap allowing molten material to seep through; Location B melts and recycles the crust
Location A melts and recycles the crust; Location B creates new ocean crust
Answer:
C hope it helps
Explanation:
Answer:
location A creates a volcano
Explanation:
mark as brainliest
Which of the following is NOT an environmental threat from the use
of coal?
Select one:
O a Water Pollution
Ob Sound Pollution
Oa Solid Waste Buildup
O d. Air Pollution
Pls help me with this chemistry work.
This seems to be a Hess' Law problem. Hess' Law states that "states that regardless of the multiple stages or steps of a reaction, the total enthalpy change for the reaction is the sum of all changes." (Libretext)
Compare the step reaction to the final reaction to see the similarity and differences. We may have to flip an equation or multiply it by a constant to obtain the number of moles of the species in the final equation. Just remember, whatever we do to the equation, we have to do to the ΔH as well.
3C + 4H₂ → C₃H₈ ΔH= +104 kJ [1]
C + O₂ → CO₂ ΔH= -394 kJ [2]
2H₂ + O₂ → 2H₂O ΔH= -572 kJ [3]
C₃H₈ + 5O₂ → 3CO₂ + 4H₂O ΔH = ?
_____________________________________________
Compare the Equation
Equation [1]
In [1] the C₃H₈is on the product side. But the final equation has the C₃H₈ on the reactant side. Thus we have to flip the equation. This flips the sign of ΔH.
C₃H₈ → 3C + 4H₂ ΔH= - 104 kJ [1]
Equation [2]
The CO₂ in the final equation is on the product side but is 3 moles. Thus we have to multiply [2] by three. The ΔH is also multiplied by 3.
3C + 3O₂ → 3CO₂ ΔH= 3 (-394 kJ) [2]
Equation [3]
The H₂O in the final equation has a coefficient of 4. Thus we have to multiply [3] by 2.
4H₂ + 2O₂ → 4H₂O ΔH= 2(-572 kJ) [3]
Combine the Equations
Combine the newly sorted versions of the equation and simplify to see if it matches the final equation. We also add the ΔH.
⇒ C₃H₈ + 3C + 3O₂ + 4H₂ + 2O₂ → 3C + 4H₂ + 3CO₂ + 4H₂O
ΔH= - 104 kJ + 3 (-394 kJ) + 2(-572 kJ)
⇒ C₃H₈ + + 5 O₂ → 3CO₂ + 4H₂O
ΔH= - 104 kJ + 3 (-394 kJ) + 2(-572 kJ) = −2430 kJ
∴ the ΔH of the final equation is −2430 kJ.Use the reaction to answer the question.
Zn + 2HCI - ZnCl2 + H2
Which type of reaction is this?
(1 point)
o electronegative
O replacement
combustion
O ionic
Answer:
i think its replacement
Explanation:
By definition, the correct answer is the second option: the reaction is a replacement.
A simple substitution reaction or simple displacement reaction, called single-displacement reaction, is a reaction in which an element of a compound is substituted by another element involved in the reaction.
The starting materials are always pure elements and an aqueous compound. And a new pure aqueous compound and a different pure element are generated as products.
The general form of a simple substitution reaction is:
AB + C → A +BC
where C and A are pure elements; C replaces A within compound AB to form a new co, placed CB and elementary A.
A single-displacement reaction is characterized by a place of exchange of cations or anions with another to form a new product. A begins as an ion in the solution and appears elementally in the reaction products. In case of reagent C it starts in its elemental form and ends as an ion in an aqueous state forming compound BC.
In this case, it is a single replacement reaction where 1 atom of Zinc metal displaces 2 H⁺ ions from the hydrochloric acid to form hydrogen gas and zinc chloride, a salt.
Finally, the correct answer is the second option: the reaction is a replacement.
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https://brainly.com/question/11666844?referrer=searchResultshttps://brainly.com/question/21250889?referrer=searchResultshttps://brainly.com/question/7039713?referrer=searchResults7) Muscles work to lift a bone in your arm by contracts and relaxes to
help please
Answer:
By contracting, muscles pull on bones and allow the body to move. When you want to bend your elbow, your biceps muscle contracts, and, at the same time, the triceps muscle relaxes. The biceps is the flexor, and the triceps is the extensor of your elbow joint.
Explanation:
yeah, hope it helps a little. :)
How is the molar mass of a molecule determined? What are its units?
Answer:
adding the standard atomic masses (in g/mol) of the constituent atoms.
What group is this Element in?
Group 3
Group 4
Group 7
O Group 1
Answer:
Explanation:
It contains the elements titanium (Ti), zirconium (Zr), hafnium (Hf) and rutherfordium (Rf). This group lies in the d-block of the periodic table. The group itself has not acquired a trivial name; it belongs to the broader grouping of the transition metals.
Assuming all other conditions remain the same, which of the following will cause an object's density to increase?
A) Its mass increases
B) its volume increases
C) its atoms move together
D) all of the above
Taking into account the definition of density, assuming all other conditions remain the same, increasing mass will cause an object's density to increase.
Density is defined as the property that matter, whether solid, liquid or gas, has to compress into a given space. That is, density is a quantity referred to the amount of mass contained in a given volume.
Density is an intensive property since it does not vary with the amount of substance.
Since density is the relationship between the mass and the volume of a substance, its calculation is defined as the quotient between the mass of a body and the volume it occupies:
[tex]density=\frac{mass}{volume}[/tex]
In the previous expression it can be observed that the density is inversely proportional to the volume: the smaller the volume occupied by a certain mass, the greater the density.
On the other hand, density is directly proportional to mass: the greater the mass, the greater the density.
Finally, assuming all other conditions remain the same, increasing mass will cause an object's density to increase.
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brainly.com/question/952755?referrer=searchResults brainly.com/question/1462554?referrer=searchResultsMagnesium metal is placed in sulfuric acid. The solution begins to bubble. The remaining liquid is an ionic solution..... What is the equation for this reaction.
pls balance the equation
Answer:
M g ( s) + 2 H + ( a q) + 2 S O 4 2 − ( a q) -> M g 2 + ( a q) + 2 S O 4 2 − ( a q) + H 2 ( g) The reaction forms magnesium sulfate and hydrogen gas. As the sulfate is still aqueous on either side of the equation, we can leave it out of the ionic equation (it is a spectator ion).
Explanation:
The chemical equation of Magnesium and sulfuric acid:
Mg + H₂SO₄ → MgSO₄ + H₂
What is the chemical equation?A chemical equation can be described as the equation of a chemical reaction involving substances. An equation consists of reactants contributing, formed products, and an arrow to indicate a chemical reaction.
The balanced equation of a reaction involving an equal number of atoms of substances on either side of the equation is known as a balanced chemical equation.
The law of conservation of mass will be followed by such an equation. By obeying this law, the total mass of the reactants as well as products should be equal in a balanced chemical equation.
Given the reaction of Magnesium metal placed in sulfuric acid. The solution starts to bubble as there is the formation of hydrogen gas.
Mg + H₂SO₄ → MgSO₄ + H₂
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help me pwease it's due tomorrow
Answer:
1. 50 km/hr
2. 5 m/s
3. 180 km/hr 50 m/s
4. 30.56 m/s
5. 11.4 km/hr
Explanation:
#1 500 km/ 10 hours = 50 km/hr
#2 100 m/ 20 s = 5 m/s
#3 540 km/3 hrs = 180 km/hr
180 km/1 hr x (1000 m/ 1 km) x (1 hr/ 60 minutes) x (1 minute/ 60 seconds) = 50 m/s
4) In the experiment, why do you think they started with water that was the same temp (118 °F) for each
cup?
5) For this experiment, do you think it would it matter if the cups were different sizes, thickness, or had
different amounts of water?
Answer:
4. I think that they started with water that was the same tsmpurature because if they didnt start with the same temp of water then it would be harder to tell which one was better. and could hold the most heat.
5. yes i think it would matter, because if you have more water in one cup it might stay warmer than it would with the cups with less water, and if it was thicker it would hold mor heat because it is not so thin that the heat is just gonna come out it has to come through more for the heat to get out.
Explanation:
sorry if these are to long but thats how i would answer them.
hope it helped
An electric current is passed through water and bubbles start forming. What is a logical conclusion for the bubbles?
A) water is evaporating
B) The water had impurities
C) A physical changes occurred
D) Hydrogen and oxygen are being formed
Which two elements in the d block do not transition and what are their changes when they make ions?
Answer:
scandium or zinc i think
Explanation:
Which halogen has 5 energy levels?
O iodine
bromine
Xenon
O nitrogen
Answer:
nitrogeno
Explanation:
creo xdddd
Answer:
bromine
Explanation:
(Ar)3d10,4s2,4p5
The measure of the average kinetic energy of molecules is known as
Answer:
Temperature is a measure of the average kinetic energy of the particles in a substance.
Explanation:
explain the classification of elements into block
Answer:
Explanation:
The elements in the long form of periodic table are classified into four blocks. They are s, p, d and f-block elements. The classification is based on the name of orbitals which receive the last electron. The elements in which the valence shell electron enters the s-orbital are called s-block elements.
Use the diagram below to answer the Question.
Which convection zone region is shown at point 3?
Question 6 options:
polar region
temperate region
tropical region
Answer:
It should be tropical
Explanation:
tropical is the closest to the equator
BRAINLIEST?
What type of bond exists when valence electrons are collectively attracted to positively-charged nuclei but are still mobile enough to travel among all of the nuclei?
a) ionic
b) metallic
c) covalent
d) London dispersion
Answer:
Ionic bond
Explanation:
What do light bulbs emit to produce light?
Group of answer choices
protons
electrons
neutrons
photons
Light bulbs emit photons to produce light. Photons are packets of electromagnetic energy, and when an electric current passes through the filament of a light bulb, it heats up and produces light. Option D is correct.
When an electric current passes through the filament of a light bulb, the filament gets heated up due to the resistance of the material. This heating process causes the filament to become incandescent, meaning it emits light as a result of being heated to a high temperature.
The emitted light consists of photons, which are particles of electromagnetic energy. These photons carry the energy released from the heated filament in the form of electromagnetic waves, resulting in the visible light that illuminates the surrounding area. Protons, electrons, and neutrons are subatomic particles and are not involved in the process of emitting light in a light bulb.
Hence, D. is the correct option.
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--The given question is incomplete, the complete question is
"What do light bulbs emit to produce light? Group of answer choices A) protons B) electrons C) neutrons D) photons."--
what is the maximum number of electrons that can exist in the g sublevel?
Answer:
14 electrons max
Explanation:
The s sublevel just has one orbital, so can contain electrons max
Lighting a match is an example of what kind of energy conversion?
A. Chemical potential energy being converted to heat energy
B. Chemical potential energy being converted to kinetic energy
C. Gravitational potential energy being converted to heat energy
D. Kinetic energy being converted to chemical potential energy
Answer:
Mechanical Energy to Thermal Energy
When you strike a match, it moves through the air until it rubs against a surface. The rubbing produces the heat required to light the match. This is a transformation from mechanical energy to thermal (heat) energy.
Explanation:
Answer:
A is the answer.
Explanation:
Cho biết X, Y (ZX < ZY) là hai nguyên tố mà lớp vỏ nguyên tử có electron cuối cùng điền vào phân lớp 4s.
a/ Viết cấu hình electron của X, Y.
b/ Viết kí hiệu nguyên tử của X, Y.
If you compare the mass of a
substance before and after a
change, what will you find?
A. The mass before is greater than after.
B. The mass before equals the mass after.
C. The mass after is greater than before.
Answer:
the answer is (B)
the mass before equals the mass after
nucleolus what is a nucleolus
Answer:
Its a small dense spherical structure in the nucleus of a cell during interphase.
why is sodium chloride solution a good conductor of electricity but does not have any effect on litmus paper?
Answer:
Sodium chloride solution contain free electron to conduct electricity. But in solution is not acid or basic media that is why not active in litmus paper
Explanation:
The sodium chloride solution a good conductor of electricity but does not have any effect on litmus paper because sodium chloride solution have free electron to conduct electricity. But in solution is not acid or basic media.
Why is sodium chloride solution a good conductor of electricity?The sodium atoms and chlorine atoms separate when sodium chloride dissolves in water due to the influence of the water molecules. They are free to move as positively and negatively charged ions in the water. This charge separation enables the solution to conduct electricity.
Because cane sugar is a covalent compound bonded by electron sharing, a solution of cane sugar does not conduct electricity. There are no ions in the solution to conduct electrical charges across the solution.
Thus, sodium chloride solution have free electron to conduct electricity. But in solution is not acid or basic media.
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Methane's chemical formula is CH. Is there a bond between any of the hydrogen atoms? Why or why not? (1 point)
O No, there is not because carbon needs four bonds, so it bonds with each hydrogen atom; hydrogen only forms one bond.
Yes, there is because they form a long chain in order to all have stable outer energy shells.
O No, there is not because it would form H2 instead of methane if hydrogen bonded with itself.
Yes, there is because there are one too many hydrogen atoms for carbon to handle alone, so one hydrogen must bond with another.
Answer:
No, there is not because it would form H2 instead of methane if hydrogen bonded with itself.
Explanation:
from the shape of methane which is tetrahedral it's evident there's no hydrogen bond only C-H bond.
The chemical formula of methane is [tex]CH_4[/tex] but: C. No, there is no bond between any of the hydrogen atoms because it would form [tex]H_2[/tex] instead of methane if hydrogen bonded with itself.
A chemical bond is defined as the forces of attraction existing between ions, crystals, atoms or molecules and they are mainly responsible for the formation of chemical compounds.
This ultimately implies that, a chemical bond refers to a force holding two or more atoms together and binding ions, crystals, or molecules together, in order to form a chemical compound.
Methane comprises of an atom of carbon and four (4) atoms of hydrogen.
Basically, hydrogen only shares a single (one) valence electron with carbon but not itself (hydrogen atoms) to form methane because of the [tex]sp^3[/tex] hybridization.
Hence, there is no bond existing between any of the four (4) hydrogen atoms because it would form [tex]H_2[/tex] instead of methane ([tex]CH_4[/tex]), if hydrogen bonded with itself.
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What is H2O (water) classified as? Question 4 options: a molecule an atom an element a diatomic molecule
Answer:
its classified as a molecule