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
Eduardwww [97]
3 years ago
9

Can u please help me I don't understand it and if I don't do it my teacher will get really mad at me pleas

Chemistry
1 answer:
Nana76 [90]3 years ago
6 0

Physical Change: It is a type of change in which matter changes its physical state like shape, size but is not transformed into another substance. It is usually a reversible process.

Chemical Change: It is a type of change in which the rearrangement of atoms of one or more than one substance is involved.  and it changes its chemical composition that is there is a formation of at least one new substance. It is usually an irreversible process.

Now, keeping in mind the definitions, we can easily classify the examples in the question as physical or chemical change.

7. Chemical Change

8. Chemical Change

9. Physical Change

10. Chemical Change

11. Physical Change

12. Physical Change

13. Chemical Change

14. Physical Change

15. Chemical Change

16. Physical Change

17. Chemical Change

18. Chemical Change

19. Physical Change

20. Physical Change

21. Chemical Change

22. Physical Change

23. Chemical Change

24. Chemical Change

25. Physical Change

You might be interested in
A solution is prepared by adding 100 mL of 1.0 M HC₂H₃O₂(aq) to 100 mL of 1.0 M NaC₂H₃O₂(aq). The solution is stirred and its pH
anastassius [24]

Answer: Option (c) is the correct answer.

Explanation:

When an acid or base is added to a solution then any resistance by the solution in changing the pH of the solution is known as a buffer.

This is because a buffer has the ability to not get affected by the addition of small amounts of an acid or a base. As a result, it helps in maintaining the pH of the solution.

In the give case, when we add the HCl then more number of protons will dissociate. This causes the acetate to react with the protons and leads to the formation of acetic acid.

We know that acetic acid is a weak acid and it dissociates partially or feebly. Therefore, no change in pH will take place.

Thus, we can conclude that equation H_{3}O^{+}(aq) + C_{2}H_{3}O^{-}_{2}(aq) \rightarrow HC_{2}H_{3}O_{2}(aq) + H_{2}O(l) represents the chemical reaction that accounts for the fact that acid was added but there was no detectable change in pH.

3 0
4 years ago
During meiosis, only one chromosome from each homologous is passed on to the offspring. What does this help increase?
Helga [31]
This helps increase variation in the offspring.
6 0
3 years ago
The number of grams of H2 in 1470 mL of H2 gas. ​
Lorico [155]

Answer:

0.1313 g.

Explanation:

  • It is known that at STP, 1.0 mole of ideal gas occupies 22.4 L.
  • Suppose that hydrogen behaves ideally and at STP conditions.

<u><em>Using cross multiplication:</em></u>

1.0 mol of hydrogen occupies → 22.4 L.

??? mol of hydrogen occupies → 1.47 L.

∴ The no. of moles of hydrogen that occupies 1.47 L = (1.0 mol)(1.47 L)/(22.4 L) = 6.563 x 10⁻² mol.

  • Now, we can get the no. of grams of hydrogen in 6.563 x 10⁻² mol:

<em>The no. of grams of hydrogen = no. of hydrogen moles x molar mass of hydrogen</em> = (6.563 x 10⁻² mol)(2.0 g/mol) = <em>0.1313 g.</em>

5 0
3 years ago
A medical research lab in Europe is studying a drug’s absorption in the blood. Another lab in Japan is trying to delay the elimi
ladessa [460]

The correct answer is From different social and ethnic backgrounds.

Explanation:

The purpose of science studies is to gain an understanding of specific phenomena and use this in the benefit of the world or humanity. Moreover, science is guided by objective methods and these are applied all around the world. This feature allows scientists from all kinds of social and ethnic backgrounds to study the same phenomena and obtain similar results, which is essential for the progress of scientific knowledge. This is exemplified by two different labs in two different countries studying drug absorption because the results of these two studies can be analyzed together to understand drug absorption.

In this context, one factor that contributes to the progress of scientific knowledge is the effort of scientists "from different social and ethnic backgrounds".

7 0
4 years ago
The most simple level of organization in living things is the tissue level.
murzikaleks [220]
<span>The simplest level of organization for living things is a single organelle, which is composed of aggregates of macromolecules. so it is false</span>
3 0
3 years ago
Read 2 more answers
Other questions:
  • Write a balanced nuclear equation for the alpha decay of americium-241
    6·1 answer
  • How many chlorine molecules are in 6.5 moles of chlorine
    14·2 answers
  • Using a blow dryer to dry your hair is an example of conduction, convection, or radiation?
    14·2 answers
  • Select the correct identity of glacial acetic acid.
    15·1 answer
  • Give criteria in terms of temperature changes for exothermic and endothermic reactions
    10·1 answer
  • The parts of the scientific method have to be followed in one specific order in all investigations. True False
    10·1 answer
  • HELP NOW!!Why is it important to classify living organisms?
    12·1 answer
  • The mass of 100cm3 of water is 100 g. Use the formula to calculate its density.
    10·2 answers
  • a 5.og of sample of compound dissolve in enough water to form 100ml of a solution .this solution form osmotic pressure of 25 tor
    14·1 answer
  • The number of Al atoms in 0.25 mol of Al2(SO4)3​
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!