Earlier species thanks to evolution. hope this helped!
Answer:
7.186
Explanation:
The mean is the average of some given data from a sample point.
To calculate the mean, we use the formula below:
Mean = ∑fx/∑f
Where f = frequency
x = sample data
From the given pH of the solutions, we can form a table:
x f fx
7.15 1 7.15
7.16 1 7.16
7.18 1 7.18
7.19 1 7.19
7.20 3 21.6
7.21 1 7.21
Now ∑fx = 7.15 +7.16 +7.18 + 7.19 + 7.20 + 7.21 = 57.49
∑f = 1 + 1 + 1 + 1 + 3 + 1 = 8
The mean =
= 7.18625 = 7.186
Answer:
"23.896%" is the right answer.
Explanation:
The given values are:
Mass of NaCl,
= 51.56 g
Mass of H₂O,
= 165.6 g
As we know,
⇒ Mass of solution = 
= 
= 
hence,
⇒ 


Answer:
3.18 mol
Explanation:

n(CO2) = mass/ Mr.
= 25.5 / 16
= 1.59 mol
As per the equation above,
n(LiOH) : n(CO2)
2 : 1
∴ 3.18 : 1.59
Answer:
no.
Explanation:
The reason this has
never happened is due to the source of magnetic fields: moving electric
charges. When electric charges (e.g. electrons) move in circles, they
produce a magnetic field. In a piece of iron, it is very easy to line up
these circles, getting all the little magnets to work together as one big
magnet.
For each of these circles, one side is the north pole and one side is the
south pole. Since each circle has two sides, each circle has a north and a
south pole. Even the smallest possible magnets (spinning electrons) have a
north and a south pole.