Answer: Option (b) is the correct answer.
Explanation:
A change that does not lead to any difference in chemical composition of a substance is known as a physical change.
For example, shape, size, mass, volume, density, boiling point, etc of a substance are all physical properties.
On the other hand, changes that lead to bring change in chemical composition of a substance is known as a chemical change.
For example, exploding dynamite, rotting cheese, combustion, oxidation etc are all chemical changes.
Thus, we can conclude that the statement a physical change is a change from one state of matter to another; a chemical change results in a new substance formed, is correct.
Answer:
The volume of water measured is 10mL
Explanation:
Given;
Mass of mass of beaker and the water = 23.670 g
Mass of empty beaker = 13.712 g
Then, mass of water only = Total mass of of beaker and the water minus Mass of empty beaker
mass of water only = 23.670 g - 13.712 g = 9.958 g
Density = mass/volume
Given density of water = 0.9982071 g/mL
Density of water = Mass of water/ Volume of water
Then, Volume of water = Mass of water/Density of water
Volume of water = 9.958 g/0.9982071 g/mL
Volume of water = 9.975886 mL ≅ 10mL
Therefore, The volume of water measured is 10mL
Answer:
See explanation below
Explanation:
To solve this problem, we need to use the expression of half life decay of concentration (or mass) which is the following:
m = m₀e^-kt (1)
In this case, k will be the constant rate of this element. This is calculated using the following expression:
k = ln2/t₁/₂ (2)
Let's calculate the value of k first:
k = ln2/2.7 = 0.2567 d⁻¹
Now, we can use the expression (1) to calculate the remaining mass:
m = 8.1 * e^(-0.2567 * 2.6)
m = 8.1 * e^(-0.6674)
m = 8.1 * 0.51303
m = 4.16 mg remaining
D is an alkene because the ending is cis-2-pentene if it was an alkane is would be pentane.
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