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
Akimi4 [234]
3 years ago
12

Physical and chemical change

Chemistry
2 answers:
Greeley [361]3 years ago
5 0
physical change in a substance doesn't change what the substance is. In a chemical change where there is a chemical reaction, a new substance is formed and energy is either given off or absorbed. For example, if a piece of paper is cut up into small pieces it still is paper.
lina2011 [118]3 years ago
5 0

Chemical change: a change that occurs when one substance combines with another substance to make a new substance

Physical change: a change to any physical property of a substance


You might be interested in
What is the function of this instrument?
chubhunter [2.5K]
To measure weight of a item
7 0
3 years ago
If 75 grams of oxygen react, how many grams of aluminum are required?
german

Answer:

84.24 g

Explanation:

Given data:

Mass of oxygen = 75 g

Mass of Al required to react = ?

Solution:

Chemical equation:

4Al + 3O₂     →   2Al₂O₃

Number of moles of oxygen:

Number of moles = mass/ molar mass

Number of moles = 75 g/ 32 g/mol

Number of moles = 2.34 mol

Now we will compare the moles of oxygen with Al.

                          O₂         :          Al

                           3          :             4

                        2.34        :         4/3×2.34 = 3.12 mol

Mass of Al required:

Mass = number of moles × molar mass

Mass = 3.12 mol × 27 g/mol

Mass = 84.24 g

5 0
2 years ago
Identify the acids and the bases in the chemical equation ​
agasfer [191]
<h3><u>Answer;</u></h3>

Acids;  HCl and HC5H5N+

Bases; C5H5N and Cl-

<h3><u>Explanation;</u></h3>
  • According to Bronsted-Lowry Theory an acid is a proton or hydrogen ion donor while a base is a proton or a hydrogen ion acceptor.
  • In this case,<u> both HCl and HC5H5N+ are acids</u> as <u>they are donors of hydrogen ions</u>. HCl is an acid to the forward reaction while HC5H5N+ is a acid to the reverse reaction.
  • On the other hand, <u>C5H5N and Cl- are bases</u>, <u>they are acceptors of hydrogen  ions</u>. Cl-  is a base in the reverse reaction while C5H5N is a base in the forward reaction.
8 0
3 years ago
10. Which of the following mirror is used to form smaller image
vitfil [10]

Answer:

Correct answer is b) convex mirror

Explanation:

A convex mirror, which bulges outward, reflects at a wider angle near its edges than at its center, creating a slightly distorted image that's smaller than actual size. Convex mirrors have many uses. The smaller size of the images means that you can see more with these surfaces, hence their use in safety mirrors.

3 0
3 years ago
The device shows the relative humidity at 22°
sergeinik [125]
The relative humidity shows us saturation of water in air. Since it is 58% and not 100% we have to scale density that we were given when humidity is 100%.

At 100% humidity, density is 20grams/cubic meter

at 58% it will be:
0.58 * 20 = 11.6 g/m^3

Since the question is to find density, the answer cannot be in %.

Answer is 11.6 g/m^3
4 0
3 years ago
Read 2 more answers
Other questions:
  • Which of the phases below are NOT able to be compressed
    5·1 answer
  • Complete the following sentence. In a fluid, pressure __________ with depth. increasesdecreasesdoesn't change
    14·1 answer
  • Physics 130 Metal detectors, like the ones used at airports, are activated by a. electric fields. b. magnetic fields. c. electro
    5·1 answer
  • Scoring Scheme: 3-3-2-1 Part III. For each trial, enter the amount of heat gained by the chemical system of ammonium nitrate, qr
    12·1 answer
  • A gas has a pressure of 2.31 atm and occupies
    8·1 answer
  • Which term below represents a pure substance that can be separated chemically, but cannot be separated physically, that is made
    8·2 answers
  • What is the name of the people who hid the Dead Seas Scrolls. When did they live at Qumran?
    9·1 answer
  • HELP ME ASAPPPP PLZZZZZ!!!!!
    15·1 answer
  • How many moles of water are produced when 2 moles of NaHCO3 react with 2 moles of HCI?
    12·1 answer
  • Can someone define these for me
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!