describe the development of the theory of atomic structure
this question is worth 6 marks

Answers

Answer 1
The atomic theory, which holds that matter is composed of tiny, indivisible particles in constant motion, was proposed in the 5th cent. BC by the Greek philosophers Leucippus and Democritus and was adopted by the Roman Lucretius. However, Aristotle did not accept the theory, and it was ignored for many centuries.

Related Questions

What could be a reason for the difference between the theoretical and experimental heats of reaction

Answers

Answer:

Theoretical value is the value a scientist expects from an equation, assuming perfect or near-perfect conditions. Experimental value, on the other hand, is what is actually measured from an experiment. Rarely (in fact never) are these numbers the same.

Take the area of a sheet of paper. I know that the area of a rectangle can be found by multiplying the lengths of both sides together. I can assume an 8.5x11 sheet, so I calculate exactly 93.5 square inches. This is my theoretical value. When I actually do the measurements on my paper, it turns out my paper has been slightly cut on one end, or I’m measuring with a shoddy ruler. Therefore, I might measure only 92.8 square inches. This is my experimental value. See thats it’s close, but not exact.

Expanding on this concept, quantum mechanics is so widely accepted in the scientific community because many theoretical values calculated by mathmaticians concurred with experimental values to many, many decimal places. These would be constants such as Plank’s Constant, energy levels of harmonic potentials, and energy levels of the hydrogen atom.

Explanation:

Theoretical result is based on information and mathematics. Trials or experiments are the foundation of experimental result. What ought to occur is theoretical probability. What actually occurs is experimental probability.

What is difference between theoretical and experimental result ?

The definition of theoretical probability. It is not necessary to do the experiment and then analyze the findings for theoretical probability. The theoretical probability, however, represents what you anticipate will occur in an experimnet.

In experimental probability, information is gathered via repeated experimentation. In theoretical probability, data is gathered without doing the experiment by taking into account every possibility that has a chance of occurring.

Thus, difference between the theoretical and experimental heats of reaction the incomplete combustion may result in the formation of carbon and carbon monoxide instead of carbon dioxide and water.

To learn more about difference between theoretical and experimental result refer the link below;

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PLZ HELP i need it now

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If maybe you can state what you’re writing about

how many valence electrons are there in a magnesium atom?

Answers

Answer:

Magnesium has 2 valence electrons.

In the chloroplast, energy in sunlight is passed around different chlorophyll molecules until it reaches a specific chlorophyll molecule that can transfer energy in sunlight to an energized electron. This chlorophyll molecule is called the accessory pigment. electron-carrier molecule. nucleus. photoelectric point. reaction center.

Answers

Answer:In the chloroplast, energy in sunlight is passed around different chlorophyll molecules until it reaches a specific chlorophyll molecule

Explanation:

Answer: In the chloroplast, energy in sunlight is passed around different chlorophyll molecules until it reaches a specific chlorophyll molecule

the electron configuration of an element describes _____.

Answers

Answer:

here

Explanation:

This is the electron configuration of the element carbon.

Atoms: SC.8.P.8.7

Match the definition to proper definition:

Term:

Definition:

1. Atoms

A.Positive subatomic particles found in the

nucleus of the atom

2. Neutron

B. Negative subatomic particle found in the cloud

3. Proton

C. Substance that has no electrical charge

4. Nucleus

D. Basic building block of all matter

5. Electron cloud

E. Substance that consists of only one type of ato,

6. Electrons

F. Center of an atom with a positive charge

G. Outside of the atom with a negative charge

7. Element

Answers

Answer:

1 = D

2 = C

3 = A

4 = F

5 = G

6 = B

7 = E

Question 1 (2 points)
Which option can be classified as a pure substance?

Question 1 options:

heterogenous mixture


solution


homogenous mixture


compound

Question 2 (2 points)
Law of conservation of mass states that:

Question 2 options:

matter is destroyed


matter does not change


matter is neither created nor destroyed


matter is created

Question 3 (2 points)
What is a property of bases?

Question 3 options:

all of the above


Sour taste


Slippery touch


Ability to form hydronium ions+

Question 4 (2 points)
Which property do solutions with low pH values have?


What does it mean to have a neutral pH? - Aseptic Health

Question 4 options:

have a -OH group


feels slippery


turns litmus paper blue


tastes sour

Question 5 (2 points)
How do the products of chemical reactions compare to their reactants?

Question 5 options:

The products often have completely different properties than the reactants.


The products are usually more toxic than the reactants.


The products usuallyhave more mass than the reactants.


The products usually have more atoms than the reactants.

Question 6 (2 points)
Which of the following is an example of a physical change?

Question 6 options:

Water freezing into ice.


A piece of wood burning.


A toy car rusting.


Zinc producing hydrogen gas when mixed with water.

Question 7 (2 points)
What might happen if you mixed a strong acid with an equally strong base?

Question 7 options:

You would see an explosive chemical reaction.


The base would destroy the acid.


You'd wind up with a pH-neutral salt and water.


The acid would destroy the base.

Question 8 (2 points)
In the equation shown, what are the reactants?

2H2+O2àH2O

Question 8 options:

Hydrogen and oxygen molecules (2H2 and O2 )


Ice crystals


Hydrogen atoms (H)


Water molecules (H2O)

Question 9 (2 points)
Which phrase most accurately describes a chemical change?

Question 9 options:

A change in form


A change in taste


A change on the molecular level


A change in appearance

Question 10 (2 points)
What does it mean when there is a physical change?

Question 10 options:

A new substance has been formed.


Matter has changed from one substance into a new substance.


Matter has changed size, shape or form


Matter has changed on the molecular level.

help pls ill give 20 points!

Answers

Answer:

I didn't KNOW WHAT IS THE ANSWWR OF YOUR QUISTION IM SO SORRY

Explanation:

I WANT TO INTRODUCE SELF TO YOU CAN I

how many electrons need to be lost or gained by Ca to attain noble gas electron configuration?

Answers

Answer:

six electrons need to be gained

Explanation:

Calcium has two valence electrons. To have a stable amount of valence electrons, or to attain noble gas electron configuration, an element needs to have eight valence electrons. Now, it's just a simple math problem. How many  more valence electrons does calcium need to get to eight? It needs six, since eight minus two is six.

Hopefully that's helpful! :)

Review the information from the documents you read for this assignment. Use what you learned to answer the following question. What were the major effects of a dust storm? Give your answer in at least four sentences.

Answers

Answer:

what people experienced during a dust storm

how people reacted to a dust storm

what people did after a dust storm

Explanation:

i passed

Answer:

what people experienced during a dust storm

how people reacted to a dust storm

what people did after a dust storm

Explanation:

for each type of geometry in the simulation, examine the resulting bond angles by clicking the show bond angles checkbox. based on your observations for each geometry, provide the bond angles at the indicated locations for the two-dimensional representations of the three-dimensional structures.

Answers

The bond angles in PCl5 are 90° and 180° respectively. The bond angle in NH4^+ is 109°.

Bond angles refer to the angle between two atoms bonded to the same central atom. Several factors such as electronegativity difference and presence or absence of lone pairs on the central atom all affect the bond angle.

For NH4^+, the indicated bond angle is 109° and the specie is tetrahedral. For the specie, SF6, the indicated bond angles are 90° and 180° respectively. For HCN, the indicated bond angle is 180°. For PCl5, the indicated bond angles are 90° and 180° respectively.

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which temperature scale avoids negative temperatures

Answers

Answer:

See below:

Explanation:

Hello! My name is Galaxy and I will be helping you today. I hope you are having a nice day.

There are 3 main ways to measure temperatures, you have Celsius, Fahrenheit, and Kelvins.

Celsius and Fahrenheit are main ways to measure heat in non-scientific terms, althought they are used sometimes when needed.

Kelvins are used for Science as they are precise and can deal with temperatures that are super hot or super cold.

The lowest temperature in Kelvins is 0 degrees Kelvin, also known as Absolute Zero. There are no temperatures above that. So the answer to your question would be Kelvins.

JWhat type of evidence is gathering information through your senses or using scientific tools?

Predictions
Results
Scientific research
Observations

Answers

Observations etc etc

Element Dy has 3 known isotopes. If.2% of the sample has a mass of 160
amu, .06% has a mass of 160.9 amu and the remaining has a mass 162
amu, what is the predicted mass of Dy?

Answers

Answer:

this girl in my class is getting a dog

Explanation:

but shes annoying so im hit her

What were the first 5 planets that were observed? Why were those the only ones? Help pls!

Answers

Mercury Venus mars Jupiter Saturn

Which of the following is/are considered alcohols?
a CH3OH
b CH3CH2OH
C CH3CH2CH2OH
d All of the above

Answers

Answer: THE ANSWER IS D

Explanation:

an alcohol is a hydrocarbon chain with an hydroxyl group (OH)

A, B, AND C ARE ALL ALCOHOLS, SO THE ANSWER IS D

A clasping handshake may be used as an analogy for an enzyme-catalyzed reaction because it represents the specific manner in which an enzyme ________. folds to form secondary and tertiary structures interacts with water binds substrate is denatured by low pH

Answers

A clasping handshake is similar to the way in which enzymes bind to substrates in enzyme-catalyzed reactions.

Enzymes are biological catalysts that speed up the rates of biological reactions by lowering the minimum energy required by reactants in order to arrive at products.

Enzymes are able to achieve this feat by substrate-enzyme binding. The substrate binds to the enzyme in its active site, becomes products, and the products are released from the active site of the enzyme. Thus, the enzyme is free for the binding of another substrate.

More on enzyme-catalyzed reactions can be found here: https://brainly.com/question/6658074


11) When sodium metal is subjected to violet light, it causes the photoelectric effect. However, red light does not affect
the sodium. Explain this phenomena.

Answers

The maximum wavelength for which photoelectric effect occurs in sodium is 400 nm.

Photoelectric effect has to do with the ejection of electrons from a clean metal surface when energy is supplied in the form of light. All wavelengths of light are not capable of achieving photoelectric effect.

There exists a maximum wavelength that the incident rays must posses in order for photoelectric effect to occur. The maximum wavelength for which photoelectric effect occurs in sodium is 400 nm.

The wavelength of red light is around 625 - 740 nm which is far longer than the wavelength of violet light which is around 380 - 425 nm. Hence, when sodium metal is subjected to violet light, it causes the photoelectric effect but red light does not affect the sodium metal.

Learn more: https://brainly.com/question/865531

The salt which in solution gives a pale green precipitate with sodium hydroxide solutionanda white precipitate with barium chloride solution is?​

Answers

Answer:

Analytical Chemistry. The salt which in solution gives a pale green precipitate with sodium hydroxide solution and a white precipitate with barium chloride solution is : Iron (III) sulphate.

iron sulphate is the awnswer to your question

What are the four groups of carbon compounds found in living things?

Answers

carbohydrates, lipids, proteins, and nucleic acids

Lead has a density of 11.29 g/mL. If you had 186 g of lead, what would its volume be?

Answers

I think you just do 11.29 multiplied by 186 since to find density you divide mass by volume. So 186 divided by x is 11.29. So in conclusion the volume would be 2,099.94mL

what does not happen when the temperature is increased ?

Answers

More particles collide in the correct orientation​
I agree with the person above me, more particles do collide in the correct orientation and the particles collide more often and with more energy.

convert 120 mm to feet

Answers

Answer:

0.393701

Explanation:

0.393701 !!!!!!!!!!!!!!!!!!!

What's the Matter?
Which statements correctly describe matter? Select all that apply.
A. Matter is made up of atoms.
B. Matter is a measure of the amount of material in an object.
C. Matter may exist as a solid, liquid, or gas.
D. Matter forms when particles chemically bond together.
E. Matter includes both elements and compounds.

Answers

The answer is C for matter is made up of atoms that can turn into those three stages

Answer:

Matter is anything that takes up space and has mass. Mass is the stu that matter is made of, or the amount of particles in a substance or object. Matter has physical and chemical properties and can undergo physical and chemical changes

C. Matter may exist as a solid, liquid, or gas.

Explanation:

what is the mass percent of hydrogen in water

Answers

Answer:

11.11%

Explanation:

The percentage of an element in a compound is 100 times the fraction, so for water the mass percent hydrogen is 11.11%

Hope this helps :)

Balance this equation: _____ C3H8 + _____ O2 --> energy + _____ CO2 + _____ H2O

Answers

There will be 10 oxygens on the products side and 2 on the reactants so to balance these out, we multiply the 02 on the reactants side by 5. The final equation will be C3H8 + 502 ----> 3CO2 + 4H20.

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what do you mean by decimal number system

please give answer​

Answers

The decimal number system also called Hindu-Arabic number system or Arabic number system, comprises digits from 0-9 that are 0, 1, 2, 3, 4, 5, 6, 7, 8 & 9.

describe the manufacture of ethanol from hexane?

Answers

Answer:

This page looks at the manufacture of alcohols by the direct hydration of alkenes, concentrating mainly on the hydration of ethene to make ethanol.

The steps in the ethanol production process include milling the corn to meal, liquefying the meal by adding water and cooking, breaking down starch into sugar, using yeast to ferment the sugar to ethanol, distilling the ethanol by boiling off and condensing it by removing residual water and finally denaturing so that...


What do all atoms in a period (horizontal rows) have in common?

Answers

Answer:

All of the elements in a period have the same number of atomic orbitals. For example, every element in the top row (the first period) has one orbital for its electrons. All of the elements in the second row (the second period) have two orbitals for their electrons.

hope this helps

Explanation:

Elements in the same period are those that are in a single horizontal line from left to right. They do not share the same type of chemical reactivity as seen in groups. They only real thing that these elements share in common is the same principal quantum number, or main energy shell.

Darwin observed __________________ types of mockingbirds and finches lived in different island environments.

Answers

Answer:    

Darwin observed   many  different   types of mockingbirds and finches lived in different island environments.

10m/s for 30 seconds

Answers

Answer:

300 meters for 30 seconds

Explanation:

10*30= 300 therefore giving you your answer.

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