The amount of energy needed to change a liquid to a solid is calculated using the enthalpy of ________ and has a __________ sign on the energy value.

Answers

Answer 1
1. enthalpy of fusion 2. energy is lost but i’m not too sure of the sign

Related Questions

The most recent model of an atom is the_____.

Points: 67

Answers

Answer:

answer is electron cloud model

Can someone help please

Answers

Answer:

To achieve stability

Explanation:

Chemical reactions happen so that the atoms of the elements involved in the chemical reaction will become stable and therefore achieve stability.

Chlorine has 7 valence electrons. Describe the type of bond that sodium would have

with chlorine. Write the chemical formula of the compound these two elements would form together. (i figured it out nvm)

Answers

As chlorine has 7 valence electrons and sodium has 1 valence electron so to become stable and complete their octets sodium will become a cation by losing one electron and chlorine will form an anion and will gain one electron in this way both will become stable and an ionic bond will form between sodium and chlorine
Chemical formula:
Na + Cl —> NaCl

Can someone give me an example of a Hypothesis?

Answers

Answer:

if I eat more vegetables,then I will lose weight faster.

The modern-day quantum model of the atom is better than John Dalton’s model because it
A. has set electron orbits.
B. has positive and negative particles in the nucleus.
C. can be represented in one dimension.
D. answers many questions about atoms.

Answers

Answer:

its D. answers many questions about atoms.

The modern-day quantum model of the atom is better than John Dalton’s model because it "  answers many questions about atoms."

What is quantum model ?

This concept also referred to as the quantum mechanical and wave mechanical model, would be the cornerstone of contemporary atomic theory. The fact that an electron inside an atom may only exist in a limited range of states or energy is analogous to a standing wave.

What is John Dalton’s model ?

Dalton proposed that the concept of atoms will be used to explain the laws of conservation of mass as well as definite proportions. Imagining atoms as "solid, massy, hard, impenetrable, moving objects," he claimed that almost all matter would be composed of these tiny, indivisible particles.

Dalton also stated that almost no atom might be formed, converted into another, as well as destroyed. The complex shapes of orbitals also known as electron clouds used in the quantum mechanical atomic model are areas of space where an electron is likely to be present. So rather than being based on certainty, this model would be probability based.

Therefore, the correct answer will be option (D)

To know more about John Dalton’s model and quantum mechanical atomic model

https://brainly.com/question/12708372

#SPJ3

How can I increase the time over which the collision occurs?

Answers

Explanation:

The laws of physics determine that the force of impact increases with the square of the increase in speed. So, if you double the speed of a car, you increase its force of impact four times. If you triple the speed, the impact is nine times as great.

Observe that the greater the time over which the collision occurs, the smaller the force acting upon the object. Thus, to minimize the effect of the force on an object involved in a collision, the time must be increased.

As the ionic compound increases in
complexity, the melting point
A. increases
B. decreases
C. stays the same

Answers

Given what we know, we can confirm that as an ionic compound grows more complex, its melting point will increase.

What is an Ionic compound?An ionic compound is one in which atoms of elements share electrons between them to form compounds.These shared electrons generate powerful electrostatic forces that we refer to as ionic bonds. Electrostatic forces cause an increase in the melting point of a compound. As a compound grows more complex and adds more elements to its composition, it will gain new electrostatic forces, and thus increase its melting point.

Therefore, as an ionic compound grows more complex, its melting point will increase due to the increasing number of strong electrostatic forces present in the compound.

To learn more about ionic compounds visit:

https://brainly.com/question/9167977?referrer=searchResults

Answer: it INCREASES

if you don’t wanna read that long answer the other person put

Explanation:

The bacteria are known to be prokaryotes. Prokaryote means

A
organisms whose cells have no nucleus
B
organisms who are made of many cells
C
organisms who make their own food
D
organisms whose cells have a nucleus

Answers

Answer:

prokaryote, also spelled procaryote, any organism that lacks a distinct nucleus and other organelles due to the absence of internal membranes. ... Bacteria are among the best-known prokaryotic organisms. The lack of internal membranes in prokaryotes distinguishes them from eukaryotes.

Explanation:

Someone please help with number 9.

Answers

Answer:

Its development and progression are usually linked to a series of changes in the activity of cell cycle regulators. For example, inhibitors of the cell cycle keep cells from dividing when conditions aren't right, so too little activity of these inhibitors can promote cancer.

Superficially, the connection between the cell cycle and cancer is obvious: cell cycle machinery controls cell proliferation, and cancer is a disease of inappropriate cell proliferation. Fundamentally, all cancers permit the existence of too many cells.

Explanation:

hope it helps

Pls help I will give u points pls

Answers

Answer:

i think D

Explanation:

What type of chemical reaction is Al + FeO --> Al2O3 + Fe

Answers

Answer:

single reaction equation

Explanation:

Type of Chemical Reaction: For this reaction we have a single replacement reaction. Balancing Strategies: In this single replacement (also called displacement) reaction the Al and Fe are switching places.

A high viscosity liquid will

Answers

Answer: high viscosity fluids move sluggishly and resist deformation.

Explanation: some examples of high viscosity liquids is Honey, syrup, motor oil, and other liquids that do not flow freely

Match each term in the first column with an example in the second column. On a sheet of paper, write the letter of the answer.

1. physical property

2. chemical property

A ability to burn

3. solid

4. liquid

B rust appears on a nail C a puddle freezes

5. physical change

6. chemical change

D substance that has a definite shape and volume

E temperature or density

F substance that has a definite volume, but no definite shape

Answers

Answer:

wait can you go more in detail i can help you because i dont understand whats going on

Which statement correctly describes the relationship between molecular structure, the strength of electrostatic forces between
molecules, and the boiling point of a substance? (1 point)
The boiling point of a substance affects the strength of electrostatic forces, which can affect the molecular
structure
The boiling point of a substance affects its molecular structure, which can affect the the strength of
electrostatic forces.
Molecular structure affects the strength of electrostatic forces, which can affect the boiling point of a
substance
Stronger electrostatic forces cause a stronger molecular structure and lower boiling points

Answers

Molecular structure affects the strength of electrostatic forces, which can affect the boiling point of a substance is the statement that correctly describes the relationship between these terms.

The molecular structure is the way in which the atoms that are in a molecule are arranged in space, this is defined by a series of forces that hold the atoms together in a specific arrangement.

The boiling point is the temperature at which the vapor pressure of the liquid equals the pressure that surrounds the liquid, when this happens, the liquid transforms into gas.

For a compound to vaporize, the forces that hold the molecules together must be broken, this means that the boiling point of a compound depends on the attraction between the molecules, that is, on the forces that determine the molecular structure.

If the molecules are held together by strong electrostatic forces, it will take a lot of energy to push the molecules away from each other and the compound will have a very high boiling point.

Therefore, we can conclude that the boiling point depends on the molecular mass of the substance and the type of electrostatic forces present, that is, the bonds that the atoms establish with each other to form the molecule (molecular structure).

Learn more about molecular structure here: https://brainly.com/question/25799404

Which is the pathway of light as it travels through the eye?cornea → iris → retina → lenscornea → iris → lens → retinairis → cornea → lens → retinaretina → lens → iris → cornea

Answers

Answer:

Cornea >iris>lens >retina

Explanation:

Can't exactly figure out the answer but I think it should look like this

Answer: cornea → iris → lens → retina

Explanation: I have my ways ;>

When no more solute will dissolve in a solvent, the solution is_________.

Answers

Answer:

saturated solution because it can only dissolve upto fixed temperature

Answer:

Saturated

Explanation:

Explanation from online:

"When the solution equilibrium point is reached and no more solute will dissolve, the solution is said to be saturated. A saturated solution is a solution that contains the maximum amount of solute that is capable of being dissolved."

Stay Safe, and I hope this helps!!!!

1: How can you divide Pepper & Sand to make a solution?

Answers

To Divide Sand & Pepper to make a solution, You would need to get the base Proti and mix it with the secondary Proti than add heated water to Sand and Pepper to make the solution. Just like we went over class..

Answer:

Mixture of sand, pepper powder and salt can be separated by dissolving the mixture into water. Sand and pepper powder is insoluble in water while salt is soluble. So they are separated by the filtration method.

I am having the worst day ever, Someone please cheer me up. :( I'll mark you as brainiest. :(

Answers

Once I told a chemistry joke

I got no reaction.

What do you do with a sick chemistry teacher?

If you can't helium, and can't curium, you might as well barium.

I don't trust atoms,

I heard they make up everything

Hope I helped make ur day. :)

Between what two elements does hydrogen bonding occur?

Answers

Answer:

it can occur between hydrogen and 3 other elements

Explanation:

These elements are:

Nitrogen

Oxygen

Flourine

When a hurricane approaches land, people living directly on the
coast should always evacuate when told to do so by authorities.

Answers

Answer:

True

Explanation:

When a hurricane is dangerous enough that authorities say to evacuate, you should for your own safety.

When drawing an atom, we draw the same number of electrons as
protons


Select one:

True

False


Answers

Answer:

true

I hope it helps.

A reaction that had two compounds as reactants and two compounds as products is most likely a

Answers

double-replacement reaction

A student mixes 20.0gof white KCl crystals with distilled water in a beaker. After the mixture was stirred, no crystals are visible and the solution is clear. After several days, all of the water evaporates and white crystals are found in the beaker. Which of following pieces of experimental evidence would best help the student to confirm that a new compound had not been made and that only a physical change occurred?
a- The solution does not change color after stirring.
b- The KCl crystals are no longer visible after mixing with water.
c- There is a temperature change in the solution during the dissolving process.
d- After the water has evaporated, the white crystals in the beaker have a mass of 20.0g

Answers

Answer:d

Explanation: over time water evaporates which leaves you with the white crystals mass

A student in a beaker mixes 20.0 g of white KCl crystals with distilled water; no crystals are visible, and the solution is clear, indicating that the physical change has occurred, which is that after the water has evaporated, the white crystals in the beaker have a mass of 20.0 g; that is option d.

What is the significance of the physical change?

The physical change includes the change in the shape and size of the substances but not the chemical change, as in the case of here the crystal, which is left behind after the evaporation of the solution without any change in the chemical composition.

Hence, a student in a beaker mixes 20.0 g of white KCl crystals with distilled water; no crystals are visible, and the solution is clear, indicating that the physical change has occurred, which is that after the water has evaporated, the white crystals in the beaker have a mass of 20.0 g; that is option d.

Learn more about the physical change here.

https://brainly.com/question/17931044

#SPJ2

¿Cómo pueden los padres pasar a sus
hijos rasgos como el color de ojos?

Answers

Answer:

Los padres transmiten rasgos o características, como el color de ojos y el tipo de sangre, a sus hijos a través de sus genes. Algunas condiciones de salud y enfermedades también pueden transmitirse genéticamente. A veces, en

what is mass tbh pls he;p

Answers

Answer:

how much matter is in an object

Explanation:

which is the first news paper of Nepal​

Answers

Answer:

Nepal Bhasa Patrika

Explanation:

Nepal Bhasa Patrika

Sounds with great amplitude are ____________

Answers

Answer: LOUDER

Explanation:

. A larger amplitude means a louder sound, and a smaller amplitude means a softer sound.

WILL GIVE BRAINLIEST


Which model provides more information-a chemical formula or a sketch of the molecule

like in the structural formula? Explain your reasoning.

Answers

Answer:

Explanation

:Both b/c a chemical formula tells you how many and a sketch formula shows how they are bonded together.

Molecular formulas show how many atoms of each element one molecule of a compound contains. Note: Ionic compounds are generally crystalline solids with high melting points. Other compounds, however, have very different properties.

1. 4Na + 02 → 2Na20
find the reaction

Answers

oxidation reaction

Explanation:

2 Na2O → 4 Na + O2

This is an oxidation-reduction (redox) reaction:

4 NaI + 4 e- → 4 Na0(reduction)

2 O-II - 4 e- → 2 O0(oxidation)

Na2O is an oxidizing agent, Na2O is a reducing agent.

has anyone done 4.3.4 Practice: Mixtures of Matter...I need help :/

Answers

The types of mixtures are homogeneous and heterogeneous, you can identify these based on their features.

A mixture occurs when two or more materials are mixed or combined. For example, if you combine two or more liquids. Moreover, this can lead to two types of mixtures:

Homogenous mixtures.Heterogeneous mixture.

Each of these has defined features that affect the characteristics and properties of a mixture:

Homogenous mixtures:

Once the mixture is done its components cannot be easily identified.The composition is uniform.Some examples include lemonade, smoothy, and concrete.

Heterogeneous mixture:

The components can be easily identified and even separated after the mixture.The composition is not uniform.Some examples include salad, pizza and oil mixed with water.

Note: This question is incomplete because of this, I answered based on general knowledge.

Learn more about mixtures in: https://brainly.com/question/24898889

Other Questions
Identify the slope formula. i have a week to study when should i start now ? For *finals* Question 50 A whistleblower is a person who does which of the following? a. Leaks the contents of a presidential speech to the press before it is given b. Is hired in excess of the true labor requirements of an agency c. Brings to public attention gross governmental inefficiency or illegal action d. Serves in the office of the ombudsman e. Finds ways to blame others to cover for his or her inadequacies why do many people have a fraught relationship with money? how might the shape of a muscle cell be related to its function please help Felicity wants to take her DSLR camera on vacation, but she can take only one bag. Why is taking a DSLR camera with her not a good idea? Plot 1[tex]\frac{2}{5}[/tex] 12, and 2[tex]\frac{1}{10}[/tex] on the number line. Which statement is true about the function f(x)=(1/3)^x and g(x)=3^-x? a. The function have the same graphb. The graph of the function is not the samec. The graph of the function is not exponential I need help with this question ( For Music Class )Where do the notes at the bottom go onto the fretboard ? Pioneer species are the first speciesto appear after a disturbance. Whatis one significant characteristic ofpioneer species?A. They are not adapted to their surroundings.B. They are very tolerant of extreme conditions.C. They are the end product of secondarysuccession. respond with an answer not a link Explain solving how 4x 3. The length of a rectangle is 20 meters long and the width is 15 meters. Find theratio of the length to the width of the rectangle. Then simplify the ratio. A 100 watt solar power panel usually costs $146 they are on sale for 0.75 of the regular price what is the sale price What is the best way to rewrite the sentence?The quarterback passed the ball 35 yards for a touchdown,the crowd jumping up and cheering wildly.A. The quarterback passed the ball 35 yards for a touchdown.The crowd jumping up and cheering wildly.B. The quarterback passed the ball 35 yards for a touchdownthe crowd jumping up. And cheering wildly.C. The quarterback passed the ball 35 yards for a touchdownand the crowd jumped up, it was cheering wildly.D. The quarterback passed the ball 35 yards for a touchdown.The crowd jumped up and cheered wildly. . Prior to Remy's trip to Cleveland, his uncle tells him about this amazing barbecue restaurant there and raves aboutthe food and live music. Remy looks it up once he gets to Cleveland, and he finds that there are a number ofnegative reviews about it. Nevertheless, he focuses on the few positive reviews he comes across, convinces himselfthey are probably more valid than the negative ones, and decides to go to the restaurant after all. Remy has likelybeen influenced by:the availability heuristic.confirmation bias.O the representativeness heuristic.oming What will the value of the variable bags be at the end of the flowchart shown here?. Class 0 rubber gloves are used when working with voltage less than Last week the number of bacteria in a petri dish was 2.25102102. This week the number of bacteria in the petri dish is 2.75105105. How many times more bacteria are in the petri dish this week?Round the decimal to the nearest tenth.