What happens to iron when it melts?
O A. It undergoes a chemical change.
O B. It undergoes a physical change.
O c. Its atoms break apart and form new atoms.
O D. Its atoms combine and form new atoms.

Answers

Answer 1

Answer:

B. It undergoes a physical change.

Explanation:

Hello there!

In this case, since we know that chemical changes lead to the formation of new atoms and/or compounds due to the bonds rearrangement of the initial substances and the physical changes occur without changing the composition of the initial substances, we can infer that, since melting is a process that changes the phase of matter from solid to liquid without changing the identity of the initial substance, the answer to this question would be B. It undergoes a physical change. because the other options describe chemical changes.

Best regards!

Answer 2

Answer:

B. It undergoes a physical change.

Explanation:

At room temperature, the iron atoms are in an unusual loosely packed open arrangement; as iron is heated past 912 degrees Celsius, the atoms become more closely packed before loosening again at 1,394 degrees Celsius and ultimately melting at 1,538 degrees Celsius.


Related Questions

One method of increasing the chances of particles colliding during a reaction is to...
1)decrease temperature
2) decrease concentration
3)increasing concentration
4)use a catalyst

Answers

Answer:

3

Explanation:

Increasing concentration

It would probably be 3

How many moles of ammonia would be required to react exactly with 0.554 moles of copper(II) oxide in the following in chemical reaction? 2 NH3(g) + 3 CuO(s)= 3Cu(s) + N2(g) + 3 H2O(g)

Answers

The mole of ammonia in this chemical equation is 0.36933 moles of NH3... I hope it helped? :)

Determine which base will work to deprotonate each compound in an acid/base extraction.

Benzene ring with a carboxylic acid on one carbon and a methyl ester group on the opposite carbon __________
Benzene ring with a three carbon chain attached to one carbon. At the other end of the three carbon chain is a hydroxyl group. ___________
Benzene ring with a hydroxyl group attached to one carbon and a tertbutyl group attached to the opposite carbon __________-

Answers

Answer:

A common method is to perform an acid-base reaction, which can ... acid is not particularly water-soluble due to its nonpolar aromatic ring, ... An acid-base extraction can be used to extract carboxylic acids from ... carbonic acid (H2CO3) can decompose to water and carbon dioxide gas.

Explanation:

The bases that will work to deprotonate the compounds are :

NaHCO₃ or NaOH.metal alkoxidesNaOH

The Benzene ring with carboxylic acid which is a weak acid can be deprotonated using NaOH or NaHCO₃ because of the weakness of the carboxylic acid.

Metal alkoxides like potassium tertiary butoxide can be used to deprotonate a Benzene ring with three carbon chain attached to a single carbon, and also containing a hydroxyl group  is a very weak acid hence the use of Metal alkoxides.

Benzene ring with a hydroxyl group attached  is also a weak acid just like the Benzene ring with carboxylic group hence it can also be deprotonated using NaOH

Learn more : https://brainly.com/question/24664427

Solid AgCl (Ksp = 1.8 X 10-10) is placed in a beaker of water. After a period of time, the Ag+ concentration is measured and found to be 2.5 X 10-7 M.
a) What is the concentration of Cl-?
b) Has the system reached equilibrium?
c) Will more AgCl dissolve?

Answers

Explanation:

a)

[tex]k _{sp} = [Ag {}^{ + } ][Cl {}^{ - } ] \\ but \: [Ag {}^{ + } ] = [Cl {}^{ - } ] \\ k _{sp} = [Ag {}^{ + } ] {}^{2} \\ [Ag {}^{ + } ] = \sqrt{k _{sp}} \\ = \sqrt{1.8 \times {10}^{ - 10} } \\ = 1.34 \times {10}^{ - 5} mol {dm}^{ - 3} [/tex]

b)

It has not reached equilibrium because the silver concentration is not yet equal to the value of Ksp.

c)

Yes it will dissolve in order to establish the equilibrium.

PLEASE HELP REAL ANSWER NO FILE. Part A
Electricity generated from any source comes with its own advantages and
disadvantages. So, no source of energy for generating electricity is perfect. However,
imagine that there is an energy source that perfectly meets the needs of society.
Describe this ideal source of energy. Include relevant factors such as cost, supply, safety,
reliability, and environmental impact

Answers

Answer:

Wind energy

Explanation:

An ideal source of energy needs to be reliable, cost effective, safe and must lead to almost zero adverse environmental impact.

Wind energy is energy obtained from air moving at high velocity. This energy is harvested using windmills which convert mechanical energy to electrical energy.

Wind is inexpensive because it occurs naturally. However, a large expanse of land is required in order to mount sufficient number of windmills that will generate enough electrical energy for practical purposes.

This method of electricity generation is safe and does not lead to any environmental hazard unlike the burning of fossil fuels, use of nuclear energy or loss of habitat due to hydroelectric power generation.

Atmospheric pressure decreases as altitude increases. In other words, there is more air pushing down on you at sea level, and there is less air pressure pushing down on you when you are on a mountain.If pentane (C5H12), hexane (C6H14), and hexanol (C6H13OH) are heated evenly at different altitudes.

Required:
Rank them according to the order in which you would expect them to begin boiling.

Answers

Answer:

Pentane » Hexane » Hexanol

Explanation:

Pentane and Hexane are simple molecular structured with discrete molecules having weak vanderwaals forces of attraction. But Hexane has high molecular mass than pentane hence pentane has lower boiling point than Hexane.

Hexanol has hydrogen bonds between highly electronegative oxygen atom and the hydrogen atom which break on high heat energy application hence it has high boiling point.

Acts as the digestive system inside a cell. It helps to break down old or unneeded parts of the cell, and substances that have been brought into the cell from the outside. WHO I AM?

Answers

Answer:

I think it is enzymes

Explanation:

Select the statement that is FLASE about this experiment. Group of answer choices Changing metal solution will affect the redox potential. To ensure consistent data, collect the redox potential values at least three times. Changing temperature will affect the redox potential. To ensure stable reading, insert the conductivity meter in the solution for at least 60 seconds. Changing concentration will affect the redox potential.

Answers

Well arranged question is;

Select the statement that is FALSE about this experiment. Group of answer choices;

A) Changing metal solution will affect the redox potential.

B) To ensure consistent data, collect the redox potential values at least three times.

C) Changing temperature will affect the redox potential.

D) To ensure stable reading, insert the conductivity meter in the solution for at least 60 seconds.

E) Changing concentration will affect the redox potential.

Answer:

D) To ensure stable reading, insert the conductivity meter in the solution for at least 60 seconds.

Explanation:

Usually, redox potential is the measure of the ability of chemical elements to gain/lose electrons from/to an electrode respectively and after which they undergo reduction or oxidation respectively.

From online sources on experiments to determine redox potential, and taking into account the nernst equation which is; E_cell = E_0 – (RT/nF)•ln Q

Where;

E_cell is cell potential

E_0 is potential of the cell under standard conditions

R is universal gas constant

T is temperature

n is the number of electrons that are transferred in the redox reaction

F is Faraday's constant

Q is reaction quotient

Now, with all that in mind and looking at the options, the one that is false is option D.

How many grams water will condense when 56,500 joules of energy is removed from steam at its boiling point

Answers

Answer:

Start your streak by answering any question. You'll get bonus points from day 2.

The volume of a sample of carbon dioxide gas is 26.42 L at 73.0°C. What will its volume be at 92.0°C at constant pressure?

Answers

Answer:

[tex]V_2=27.87L[/tex]

Explanation:

Hello there!

In this case, according to the given information, it turns out possible for us to solve this problem by using the Charles' law a directly proportional relationship to understand the volume-temperature behavior:

[tex]\frac{V_2}{T_2} =\frac{V_1}{T_1}[/tex]

Thus, we solve for the final volume, V2, and make sure the temperature are in Kelvin as shown below:

[tex]V_2 =\frac{V_1T_2}{T_1} \\\\V_2=\frac{26.42L(92+273.15)K}{(73+273.15)K} \\\\V_2=27.87L[/tex]

Regards!

please help- science

1. - new

2. full

3. first quarter

4. last quarter

Answers

Answer:

2. Full

Explanation:

A lunar eclipse occurs at a full moon when Earth is directly between the moon and the sun. During a lunar eclipse, Earth blocks sunlight from reaching the moon.

Hope this helps!!

PLEASE HELP!! NO LINKS PLEASE REAL ANSWER!!!!!
What will be volume of 20.0 g of CH4 gas at a pressure of 0.950 atm and temperature of 21.0 oc?Question 1 options:

A. 21.8 L
B. 31.8 L
C. 2.27 L
D. 4.27 L

Answers

The answer is (C) or (D)

ch3-co-ch2-ch2-ch3 IUpAC name​

Answers

Answer:

2-pentanone.

Explanation:

Hello there!

In this case, for the given compound and, in agreement with the octet rule, it is possible to realize that the CO is actually C=O as shown below:

CH3  -  C  -  CH2  -  CH2  -  CH3

            ||

           O

Thus, since the C=O stands for the carbonyl group within the parent chain, we infer this is a ketone and more specifically 2-pentanone as it has five carbon atoms.

Regards!

What is the molarity of a solution?



the answer is The number of moles of a solute per kilogram of solvent

Answers

Molar concentration is a measure of the concentration of a chemical species, in particular of a solute in a solution, in terms of amount of substance per unit volume of solution.

1. Watch how the solubility of a gas changes as pressure is increased and then decreased during the run. Which of the following statements correctly explain the relationship between the solubility of a gas and its pressure?
A. As pressure decreases, the concentration of gas molecules in the solution increases.
B. The concentration of gas particles in the solution is higher at 4.25 atm than at 1.00 atm.
C. The solubility of a gas decreases with a decrease in pressure.
D. The solubility of nitrogen gas at 2.00 atm is twice the solubility of the gas at 1.00 atm.
E. Fewer gas molecules are soluble at higher pressures.
F. More gas molecules are soluble as pressure is increased.
G. As pressure is increased, the rate at which gas molecules enter the solution decreases.
2. At a certain temperature, the solubility of N2 gas in water at 3.08 atm is72.5mg of N2 gas/100 g water. Calculate the solubility of N2 gas in water, at the same temperature, if the partial pressure of N2 gas over the solution is increased from 3.08 atm to 8.00 atm .

Answers

Answer:

A. As pressure decreases, the concentration of gas molecules in the solution increases.

D. The solubility of nitrogen gas at 2.00 atm is twice the solubility of the gas at 1.00 atm.

F. More gas molecules are soluble as pressure is increased.

The solubility is 188.3 mg of N2 gas/100 g water.

Explanation:

As the pressure on the gas decreases, the volume of gas molecules in the solution increases due to having distance from each other. The solubility of nitrogen gas at 2.00 atm is twice the solubility of the gas at 1.00 atm because there is more pressure on the gas molecules so due to more compression, the gas becomes more soluble. More gas molecules are soluble as pressure is increased. The solubility is 188.3 mg of N2 gas/100 g water if the atmospheric pressure is increases from 3.08 atm to 8.00 atm. This value is calculated with the help of formula i.e. P2/P1 = S2/S1.

In the area with a large population of valuable ocean organisms is called a(n)

Answers

Answer:

fishery

An area with a large population of valuable ocean organisms is called a fishery. If it was correct mark me as brainiest

2x²=8.pls help me i really need it​

Answers

Explanation:

2x²=8

x²=8/2

x=√4

x=2

hope it helps.

Answer:

[tex]\huge \fbox \pink {A}\huge \fbox \green {n}\huge \fbox \blue {s}\huge \fbox \red {w}\huge \fbox \purple {e}\huge \fbox \orange {r}[/tex]

[tex] {2x}^{2} = 8 \\ {x}^{2} = \frac{8}{2} \\ {x}^{2} = 4 \\ x = \sqrt{4} \\ x = 2[/tex]

ʰᵒᵖᵉ ⁱᵗ ʰᵉˡᵖˢ

[tex] \huge\purple{ \mid{ \underline{ \overline{ \tt ꧁❣ ʀᴀɪɴʙᴏᴡˢᵃˡᵗ2²2² ࿐ }} \mid}}[/tex]

State the number of neutrons in an atom of Ne-20 and the number of neutrons in an atom of Ne-22. choose two answers * 1 point Ne 20: 10 Ne 20: 11 Ne 22: 12 Ne 22: 13

Answers

Answer:

Ne 20: 10

and

Ne 22: 12

Explanation:

Ne-20:

N = A - Z = 20 - 10 = 10 neutrons

Ne-22:

N = A - Z = 22 - 10 = 12 neutrons

N: number of neutrons

A: mass number

Z: atomic number

Name: ___________________________ Date: __________ Period: ______ Solubility Rules Practice Worksheet Name or give the chemical formula for each of the following compounds. State whether they are soluble (will dissolve) or insoluble (will not dissolve) in solution. Use solubility rules. Chemical Formula Name Solubility NH4OH Ra(OH)2 Nickel (III) Acetate CsOH RbCl Potassium Phosphate MgS CaI2 Gold (II) Hydroxide Li3PO4 Platinum (II) Carbonate Barium Nitrate

Answers

I donttt knowww sores ahahah

Given the reaction: N2(g) +2O2(g) ⇌ 2NO2(g) The forward reaction is endothermic. Determine which of the following changes would result in more product being produced.


I. Increase NO2
II. Decrease O2
III. Add a catalyst
IV. Increase the temperature
V. Increase the pressure

A. I and II
B. II, III, and V
C. IV and V
D. II and IV

Answers

Answer:

C

Explanation:

increasing the temperature will favour the forward reaction therefore the reaction system will try to counteract that by producing more heat and NO2 therefore increases the amount of products produced

increasing the pressure will favour the forward reaction as it has more moles of substance therefore if the forward reaction is favored, more product will be produced

Answer:

C.) lV and V

Explanation:

I got it correct on founders edtell

Help solve the types of chemical reactions

Answers

[tex]1) \: decomposition[/tex]

[tex]2) \:hydrocarbon \: combustion[/tex]

[tex]3) \: formation[/tex]

[tex]4) \: double - replacement[/tex]

[tex]5 \: double - replacement[/tex]

[tex]6) \: formation[/tex]

[tex]7)double \: - replacement[/tex]

[tex]8) \: double - replacement[/tex]

-. How many moles of Pb are contained in 2.49 x 1025 atoms Pb?

Answers

Answer: There are [tex]4.13 \times 10^{-3}[/tex] moles of Pb are contained in [tex]2.49 \times 10^{25}[/tex] atoms Pb.

Explanation:

According to the mole concept, 1 mole of every substance contains [tex]6.023 \times 10^{23}[/tex] atoms.

Hence, number of moles present in [tex]2.49 \times 10^{25}[/tex] atoms of Pb are as follows.

[tex]No. of moles = \frac{2.49 \times 10^{25}}{6.023 \times 10^{23}}\\= 4.13 \times 10^{-3} mol[/tex]

Thus, we can conclude that there are [tex]4.13 \times 10^{-3}[/tex] moles of Pb are contained in [tex]2.49 \times 10^{25}[/tex] atoms Pb.

How many liters of C3H6O are present in a sample weighing 25.6 grams?

Answers

To Find :

Number of moles of C₃H₆O present in a sample weighing 25.6 grams.

Solution :

Molecular mass of C₃H₆O is :

M = (6×12) + (6×1) + (16×1) grams

M = 94 grams/mol

We know, number of moles of 25.6 grams of C₃H₆O is :

[tex]n = \dfrac{Given \ Mass \ Of \ C_3H_6O }{Molar\ Mass \ Of \ C_3H_6O }\\\\n = \dfrac{25.6}{94}\ mole\\\\n = 0.27 \ mole[/tex]

Hence, this is the required solution.

True or False: Both molecules and compounds are pure substances.

Answers

Answer:

False

Explanation:

Hope this helps!

Answer:

True

Explanation:

It's because both compounds and elements are considered pure substances and a molecules is considered an element.

Show your work. 37.2 moles CO2 to oxygen atoms.

Answers

4 moles of oxygen (6.0zzx10

Observe the above circuit diagram, if the gap is filled with a plastic wire, will the bulb glow? Justify your answer

Answers

Answer:

YES THE BULB WILL GLOW.

Explanation:

BECAUSE THE CIRCUIT UPPER AREA IS MADE OF PLASTIC SO THE PLASTIC CONDUCTS THE ELECTRICITY SO THE BULB WILL GLOW.

When sodium chloride is dissolved in water, the freezing point of water _________. A. increases B. first increases, then decreases C. does not change D. decreases

Answers

The answer is D; it decreases as there are now foreign particles in the water that disperse the water molecules pushing them apart and making it harder for ice to form properly

The presence of a non-volatile salt will decrease the freezing point of water and this process is called depression in freezing point. Thus option D is correct.

What is freezing point?

Freezing point of a substance is the temperature at which it converts from its liquid state to solid state where, both the states are in equilibrium. Freezing point of water is zero degree celsius.

The freezing point of a solvent depends on some parameters such as the bond type, molecular weight, temperature, pressure etc.

When a non-volatile solute is added to the solvent its freezing point decreases from its initial value. Because presence of non-volatile salts will affect the intermolecular attraction and thereby the energy that must be applied to freeze the compound.

Therefore, the freezing point of water decreases, when sodium chloride is added into it. Thus option D is correct.

To find more about freezing point, refer the link below;

https://brainly.com/question/2292439

#SPJ6

Why do scientist conduct experiments on animals?

Answers

Answer:

Animals are used in scientific research to help us understand our own bodies and how they work. This is necessary to develop new medicines. Animals are also used to safety test potential medicines before they are tested in people and to check the safety of other chemicals.

Explanation:

3. At 34.0°C, the pressure inside a nitrogen-filled tennis ball with a volume of 148 cm3 is 212
kPa. How many moles of N2 are in the tennis ball?

Answers

Answer:

0.0123 mol

Explanation:

Step 1: Convert 34.0 °C to Kelvin

We will use the following expression.

K = °C + 273.15 = 34.0 + 273.15 = 307.2 K

Step 2: Convert 148 cm³ to L

We will use the conversion factors:

1 cm³ = 1 mL1 L = 1000 mL

[tex]148cm^{3} \times \frac{1mL}{1cm^{3}} \times \frac{1L}{1000mL} = 0.148L[/tex]

Step 3: Convert 212 kPa to atm

We will use the conversion factor 1 atm = 101.325 kPa.

212 kPa × 1 atm / 101.325 kPa = 2.09 atm

Step 4: Calculate the moles of nitrogen gas

We will use the ideal gas equation.

P × V = n × R × T

n = P × V / R × T

n = 2.09 atm × 0.148 L / (0.0821 atm.L/mol.K) × 307.2 K = 0.0123 mol


Jim makes a mixture which contains 10 mg of salt, 30 mg of sand, and some iron filings. The total mass of the mixture is 100 mg
Which amount of iron filings does Jim use in the mixture?
A10
B30
C40
D60

Answers

Answer:

Amount of iron fillings in mixture = 60 mg

Explanation:

Given:

Total mass of mixture = 100 mg

Amount of salt in mixture = 10 mg

Amount of sand in mixture = 30 mg

Find:

Amount of iron fillings in mixture

Computation:

Using Law of Conservation of mass;

Total mass of mixture = Amount of salt in mixture + Amount of sand in mixture + Amount of iron fillings in mixture

100 = 10 + 30 + Amount of iron fillings in mixture

100 = 40 + Amount of iron fillings in mixture

Amount of iron fillings in mixture = 100 - 40

Amount of iron fillings in mixture = 60 mg

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