1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Llana [10]
4 years ago
5

Describe how you would determine if a physical or chemical change has occurred

Chemistry
1 answer:
Nonamiya [84]4 years ago
5 0
A physical change is something that could be reverted back to its original form, while a chemical change is something that could not be reverted back when changed.
ex of physical change: ice - can be melted and then freeze to solid again

ex of chemical change: change of color, like adding food coloring in something and you cannot take out the color again 
You might be interested in
Moles of phosphorous in 15-35-15 fertilizer in 10g
guapka [62]

<span>The composition of a fertilizer is usually express in NPK number. NPK number is in terms of Percent by mass of the said element which are Nitrogen, Phosphorus and Potassium. A 15-35-15 fertilizer has 15% Nitrogen, 35% Phosphorous, and 15% Potassium by mass. If you have 10 g of this fertilizer, to get the number of moles of phosphorus, you multiply the mass by 35%, which is equal to 10*0.35 or 3.5 g phosphorus. Then you divide the calculated mass of phosphorous by its molar mass which is 30.97 g/mol. Therefore, you have 3.5/30.97 which is equal to 0.1130 mol Phosphorus. This is the amount of Phosphorus in moles in the fertilizer.</span>

6 0
4 years ago
In molecules, energy is stored in?<br> Atoms<br> Electrons<br> The Nucleus<br> Bonds
Nikolay [14]

Answer:

Atoms

Explanation:

Energy, potential energy, is stored in the covalent bonds holding atoms together in the form of molecules. This is often called chemical energy.

4 0
3 years ago
Calculate the molecular mass or formula mass (in amu) of each of the following substances: (a) BrN3 amu (b) C2H6 amu (c) NF2 amu
irakobra [83]

Answer:

Shown below

Explanation:

a) for BrN3

80+3(14)=122amu

b) forC2H6

2(12) + 6(1) = 30amu

C) for NF2

14+2(19) = 52amu

D) Al2S3

2(27) + 3(32)= 150amu

E) for Fe(NO3)3

56 + 3 [14+3(16)] =242amu

F) Mg3N2

3(24) + 2(14)= 100amu

G) for (NH4)2CO3

2[14 +4(1)] +12 +3(16)=96amu

5 0
4 years ago
Read 2 more answers
A 4.24 kg marble slab has the volume of 1564 cm3 What is the density in g/cm3
miskamm [114]

Answer:

The answer is

<h2>2.71 g/cm³</h2>

Explanation:

The density of a substance can be found by using the formula

density =  \frac{mass}{volume} \\

From the question

volume of marble = 1564 cm³

1 kg = 1000 g

4.24 kg = 4240 g

mass = 4240 g

The density is

density =  \frac{4240}{1564}   \\  = 2.710997442...

We have the final answer as

<h3>2.71 g/cm³</h3>

Hope this helps you

7 0
3 years ago
A penny has a mass of 2.50g and the Moon has a mass of ×7.351022kg, How many moles of pennies have a mass equal to the mass of t
baherus [9]
Answer: 122 moles

Procedure:

1) Convert all the units to the same unit

2) mass of a penny = 2.50 g

3) mass of the Moon = 7.35 * 10^22 kg (I had to arrage your numbers because it was wrong).

=> 7.35 * 10^22 kg * 1000 g / kg = 7.35 * 10^ 25 g.

4) find how many times the mass of a penny is contained in the mass of the Moon.

You have to divide the mass of the Moon by the mass of a penny

7.35 * 10^ 25 g / 2.50 g = 2.94 * 10^25 pennies

That means that 2.94 * 10^ 25 pennies have the mass of the Moon, which you can check by mulitiplying the mass of one penny times the number ob pennies: 2.50 g * 2.94 * 10^25 = 7.35 * 10^25.

5) Convert the number of pennies into mole unit. That is using Avogadros's number: 6.022 * 10^ 23

7.35 * 10^ 25 penny * 1 mol / (6.022 * 10^ 23 penny) = 1.22* 10^ 2 mole = 122 mol.

Answer: 122 mol
8 0
3 years ago
Other questions:
  • Two teaspoons of salt are added to a glass of water which is then stirred until no more salt grains can be seen. Two more teaspo
    9·2 answers
  • How many vibrational modes does ethanol have? Explain why.
    6·1 answer
  • How many atoms of phosphorus are in a 0.859 g sample?<br> Answer in units of atoms.
    10·1 answer
  • Help please it’d be greatly appreciated lol
    12·2 answers
  • What is 80% as a ratio
    13·1 answer
  • What might you expect to observe from this double-displacement reaction: CoCl2(aq) + Na2SO4(aq) ---&gt; CoSO4 + 2NaCl?
    12·1 answer
  • Nitrogen monoxide and water react to form ammonia and oxygen, like this: (g)(g)(g)(g) Write the pressure equilibrium constant ex
    13·1 answer
  • Covalent bonds form due to the attraction between _____.
    13·1 answer
  • the concept of __________ is required for certain molecules because the localized electron model assumes electrons are located b
    8·1 answer
  • Control rods in a nuclear reactor...
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!