Which is a characteristic of a physical change?

a
The chemical bonds in the substance are unchanged.

b
The change cannot be seen.

c
The molecules all move at the same speed.

d
The substance has reacted with another substance.

Answers

Answer 1
The answer for your question is a

Related Questions

What two properties of sound remain the same when sound quality differs? Check all that apply.

Answers

Answer: I don’t know sorry

Explanation:

How is oxide different from a neutral oxygen atom

Answers

Answer: The main difference between oxide and oxygen is that oxide is a chemical compound with at least one oxygen atom while oxygen is an element whose atomic number is 8.

Explanation: let me know if it was right or wrong

If the pressure in the gas tank of the dipper was set very high, the ideal Gas law breaks
down.
Why is this happening?
a) Argon reacts with the walls of the steel vessel at high pressure
b) The molecules would clump together in the center and invalidate the law
c) A steady measurement could not be made as the gas would leak out too quickly
d) The volume occupied by the molecules themselves is no longer negligible

Answers

Answer: d) The volume occupied by the molecules themselves is no longer negligible. This most be the answer because a, b and c don't make any sense at all.

Explanation:

The volume occupied by the molecules themselves is no longer negligible. Hence, option D is correct.

What is an ideal gas equation?

The ideal gas law (PV = nRT) relates the macroscopic properties of ideal gases. An ideal gas is a gas in which the particles (a) do not attract or repel one another and (b) take up no space (have no volume).

The ideal gas law fails at low temperature and high pressure because the volume occupied by the gas is quite small, so the inter-molecular distance between the molecules decreases.

Hence, the volume occupied by the molecules themselves is no longer negligible.

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Look at the following enthalpy diagram. Select all that apply.
1. The products have more energy than the reactants.
2. This is an addition reaction.
3. A large activation energy is required for this reaction to take place.
4.The products are more stable than the reactants.
5. This is a substitution reaction.

Answers

Answer:

Option 2 and 4 are correct

Explanation:

The reactants in the attached image have more enthalpy and hence less stability as they are more reactive. Thus, Product is more stable than the reactants.

This is an addition reaction in which two reactants add up to form the product.

Very less activation energy is required as the reactants themselves are unstable, possess high energy and hence are very reactive.

Reactants have more energy than the products.  

How can your body be at risk for diseases?

Answers

Answer:

I'm not sure if this is true but in science class I learned that stress can cause a risk of diseases

Explanation:

the more months of stress you have, the higher the risk

Calcular la masa de Mg que se necesita hacer reaccionar con CuSO4 para formar 1.89 g de Cu2O según la siguiente ecuación: Mg + CuSO4 + H2O MgSO4 + Cu2O + H2

Answers

Answer:

0.642 g

Explanation:

La ecuación balanceada es:

2Mg + 2CuSO₄ + H₂O → 2MgSO₄ + Cu₂O + H₂

Primero convertimos 1.89 g de Cu₂O en moles, usando su masa molar:

1.89 g ÷ 143.09 g/mol = 0.0132 mol Cu₂O

Después convertimos moles de Cu₂O en moles de Mg, usando los coeficientes estequiométricos:

0.0132 mol Cu₂O * [tex]\frac{2molMg}{1molCu_2O}[/tex] = 0.0264 mol Mg

Finalmente convertimos moles de Mg en gramos, usando la masa molar de Mg:

0.0264 mol Mg * 24.305 g/mol = 0.642 g

Write a question here it’s simple.

Answers

Answer:

what type of question?

Explanation:

whats your favorite color???

Why isn’t there a lunar eclipse every time Earth is in between the sun and the Moon?

Answers

Answer: Exploratorium Senior Scientist Paul Doherty explains why not—the orbit of the moon is tilted relative to the orbit of the Earth around the sun, so the moon often passes below or above Earth. At those times, it does not cross the line between the sun and the Earth, and therefore does not create a solar eclipse.

HOPE THIS HELPS

Why might changes to an environment cause an organism’s population to decrease?

Answers

Pollution and people littering. Can change everything.

N2(g) + 2 O2(g) → 2 NO2(g)

Answers

Answer: 1.057444301e-018

Explanation:

An amphoteric species is neither an acid nor a base. True or False

Answers

Answer: False

Explanation: just took on edge

17. What is the molarity of ZnCl2 that forms when 15 grams of Zn reacts completely with CuCl, if a
final volume of 175 mL is produced?
Zn + CuCl2 → ZnCl2 + Cu

Answers

Answer:

1.31M

Explanation:

Based on the reaction, 1 mole of Zn produce 1 mole of ZnCl₂. As the reaction occurs completely, the moles of Zn added = Moles of ZnCl₂ produced. To find molarity we need the moles of ZnCl₂ and the volume of the solution in liters:

Moles Zn = Moles ZnCl₂ -Molar mass Zn: 65.38g/mol-:

15g * (1mol / 65.38g) = 0.23 moles of ZnCl₂

Volume in Liters:

175mL * (1L / 1000mL) = 0.175L

The molarity is:

0.23moles / 0.175L

1.31M

Here is the skeleton reaction for combustion of methane (natural gas)
CH4+O2→CO2+H2O
What are the reactants of this reaction?
Please help me :(

Answers

Answer:

CH4 and O2

Explanation:

The reactants of a chemical reaction are those that are on the left side of the chemical equation. In this case, methane (CH4) and oxygen (O2) which are on the left side, are the reactants.

Can anyone tell me what the answer is?

Answers

Answer: c) A. 5.606x10²³atoms is the correct answer.

Explanation:

Which one of the following systems has the highest entropy?
10 mL of water at 100°C
10 mL of water at 50°C
10 mL of water at 10°C

Answers

Answer: a

Explanation:

The highest entropy will be 0 mL of water at 100°C.

What is entropy?

Entropy is just a measured physical quality that will be most usually linked with disorder, unpredictability, or uncertainty.

The quantity of random movement in a system increases as more energy is put into it. Entropy rises like a volume increases in a system.

Therefore, the correct answer will be option 1.

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A bow and arrow that was just pulled back but not yet released has
energy.
А
potential
B
electrical
С
geothermal
nuclear

Answers

Answer:

A potential

Explanation:

potential energy is a kind of energy which rest or stays in one position

The objects rest on a position has a potential energy. The bow and arrow that was just pulled back but not yet released has energy has potential energy.

What is potential energy ?

The potential energy of an object is generated by virtue of its position at height above the surface. It is the stored form of energy when the object is at rest. Whereas, kinetic energy of an object is generated by virtue of its motion.

When the object starts to move with a speed, its potential energy starts to convert into kinetic energy. Both are dependent on the mass of the object. And these energies are directly proportional to the mass.

Here, the bow and arrow are not moving with a speed they just pulled and stay on a position, so they don't have a net kinetic energy but they possess a potential energy. Hence, option A is  correct.

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What is the number of moles in 15.0 g AsH3?
O 5.2 mol
O 1200 mol
O 0.44 mol
O 0.19 mol

Answers

Answer:

n = 0.19 mol

Explanation:

Given mass = 15 g

The molar mass of AsH₃ = 77.94 g/mol

We need to find the number of moles in 15 g of AsH₃. We know that,

No. of moles = given mass/molar mass

[tex]n=\dfrac{15}{77.94 }\\\\n=0.19\ mol[/tex]

So, there are 0.19 g/mol. Hence, the correct option is equal to 0.19 mol.

hi does anyone know how to do chem cause I might need a tut.or or sum.
can you guys just comment if you good and ill send my sn.ap for you guys to help me id.k...
thanks anyways

Answers

Ask your parents or guardian for a tutor.

It's very dangerous to give someone your snap online that you don't know!

Have a nice day <3

This is my 6th time posting this questions. please not bots or links
and please *explain* the answer and steps
I really need help understanding this.
describe the process to determine the limiting reactant in the example listed below:
Given 3.4 grams of x element with a molar mass of 24 g/mol and 4.2 grams of y element with a molar mass of 35 g/mol. How much of compound xy2 can be generated?
x + 2y -> xy2

Answers

The amount of the compound [tex]XY_2[/tex] that can be generated would be 11.28 grams

Stoichiometric calculation

From the equation of the reaction, the mole ratio of X and Y is 1:1.

Mole of 3.5 grams of X = 3.4/24 = 0.1417 moles

Mole of 4.2 grams of Y = 4.2/35 = 0.12 moles

Thus, Y is the limiting reactant because it is present in a lower amount than needed.

Mole ratio of Y and  [tex]XY_2[/tex] = 1:1

Equivalent mole of  [tex]XY_2[/tex] = 0.12 moles

Molar mass of  [tex]XY_2[/tex] = 24 + (35x2) = 94 g/mol

Mass of 0.12 moles of  [tex]XY_2[/tex] = 0.12 x 94 = 11.28 grams

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someone help me answer this !

Answers

The answer is in the following file.
Good luck!

quick.ly/AU28D

I’m just joking the answer is B.

HELPPPPP MEEEEEE WILL OFFER BRAINLIEST

1. Which graph represents the endothermic reaction?

2. Which graph represents the exothermic reaction?

Answers

Answer:

A is endothermic, B is exothermic.

Explanation:

I actually just looked at the bottom of the graph. Endothermic reactions absorb energy, but exothermic reactions release it. Hope this helped!

A man's speed is 50 m/s and his mass is 120 kg. What is his kinetic energy just before running back up? |
kg*m/s

Answers

Answer:

150,000 Joules

Explanation:

KE= 1/2 *mv^2

1/2 * 120 *50^2

60*2500

150,000 Joules

Hope this helps :)

How many moles of sulfur
dioxide are in 2.26 x 10^33 sulfur dioxide molecules?

Answers

Answer:

moles = no. of molecules / Avogadro's number

         = 2.26 x 10^33 / 6.022 x 10^23

         = 3752906011

Round to significant figures which is 3 = 3.75 x 10^9 mol

Explanation: The formula for finding how many moles of a substance when given the amount of molecules is: moles = number of molecules / Avogadro's number

When the water inside a living cell freezes, the ice crystals damage the cell. The wood frog is a unique creature that can survive being frozen. In extremely cold

conditions, the frogs liver produces large amounts of glucose (C6H12O6), which becomes concentrated in the frog's cells. How does the glucose help prevent ice

from forming in the frogs cells?

A)The added glucose dissociates and creates faster moving molecules.

B) The added glucose lowers the vapor pressure relative to the pure solvent.

C) The added glucose requires more energy which warms the frog

D)The added glucose lowers the freezing point of the solution within the frog's cells.

Answers

but i think its B but i need answer too

A canister of neon contains 4.8x1024 atoms of the gas. How many moles of neon are present in the canister?

Answers

Answer:

7.97 moles of neon are present in the canister.

Explanation:

Avogadro's constant or "Avogadro's number" is the number of constituent particles found in the amount of substance in one mole.

In other words, Avogadro's number is the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023*10²³ particles per mole. Avogadro's number applies to any substance.

So, you can apply the following rule of three: if 6.023*10²³ atoms are present in 1 mole, 4.8*10²⁴ atoms are present in how many moles?

[tex]amount of moles=\frac{4.8*10^{24}atoms*1 mole }{6.023*10^{23}atoms}[/tex]

amount of moles= 7.97 moles

7.97 moles of neon are present in the canister.


A 148.20 sample of an unknown substance was heated from 25°C to 40°C. In the process, the substance absorbed 5683 J of energy. What is the
specific heat of the substance.

Answers

Answer: 2556.455 J/(kg.°C)

Explanation:

Im assuming the 148.20 is in grams

The equation is Q=mcΔT

Q= Heat (J)

m= Mass

c= SHC (specific heat capacity)

ΔT= Temp change

help me........................ please?

Answers

Answer:

2 NO2 -> 2 O2 + N2

is a decomposition reaction

Atomic Size: Determine which of the following element pairs is the larger one

1. Carbon or Fluorine

2. Iodine or Fluorine

3. Krypton or Argon

4. Hydrogen or Potassium

Answers

Answer: I think the answer is 3.) Krypton or Argon.

Explanation:

what simple machine would be best for lifting a couch through a 3rd floor apartment window?

Answers

Answer:

Pully

Explanation:

I would think that a pully would be most effective for lifting it Up and into the apartment (at least if you have a suitable spot to put the pully)

Which formula demonstrates a double replacement reaction?
1. A + B --> AB
2. AB + CD --> AC + BD
3. AB --> A + B
4. A + BC --> AC + B

Answers

Answer:

2

Explanation:

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