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
<h3>
Answer:</h3>
0.024 kg CaO
<h3>
General Formulas and Concepts:</h3>
<u>Math</u>
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
<u>Chemistry</u>
<u>Aqueous Solutions</u>
- Molarity = moles of solute / liters of solution
<u>Atomic Structure</u>
- Reading a Periodic Tables
- Using Dimensional Analysis
<h3>
Explanation:</h3>
<u>Step 1: Define</u>
0.41 mol CaO
2.5 M Solution
<u>Step 2: Identify Conversions</u>
1000 g = 1 kg
Molar Mass of Ca - 40.08 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of CaO - 40.08 + 16.00 = 56.08 g/mol
<u>Step 3: Convert</u>
- Set up:

- Multiply:

<u>Step 4: Check</u>
<em>Follow sig fig rules and round. We are given 2 sig figs as our lowest.</em>
0.024114 kg CaO ≈ 0.024 kg CaO
140 g of nitrogen (N₂)
Explanation:
We have the following chemical equation:
N₂ + 3 H₂ -- > 2 NH₃
Now, to find the number of moles of ammonia we use the Avogadro's number:
if 1 mole of ammonia contains 6.022 × 10²³ molecules
then X moles of ammonia contains 6.022 × 10²⁴ molecules
X = (1 × 6.022 × 10²⁴) / 6.022 × 10²³
X = 10 moles of ammonia
Taking in account the chemical reaction we devise the following reasoning:
If 1 mole of nitrogen produces 2 moles of ammonia
then Y moles of nitrogen produces 10 moles of ammonia
Y = (1 × 10) / 2
Y = 5 moles of nitrogen
number of moles = mass / molecular weight
mass = number of moles × molecular weight
mass of nitrogen (N₂) = 5 × 28 = 140 g
Learn more about:
Avogadro's number
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B the girls arm will act as a pulley
Answer:
C. 75%
Explanation:
From a heterozygous cross (Tt x Tt) the produced offspring would consist of:
- 25% TT -it would be tall-.
- 50% Tt -it would be tall as the gene T is dominant-.
- 25% tt -it would not be tall-.
Thus the produced offspring that would be tall is (50% + 25%) 75%. The answer is option C.