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
Rutherford theorized that atoms have their charge concentrated in a very small nucleus.
This was famous Rutherford's Gold Foil Experiment: he bombarded thin foil of gold with positive alpha particles (helium atom particles, consist of two protons and two neutrons).
Rutherford observed the deflection of alpha particles on the photographic film and notice that most of alpha particles passed straight through foil.
That is different from Plum Pudding model, because it shows that most of the atom is empty space.
According to Rutherford model of the atom:
1) Atoms have their charge concentrated in a very small nucleus.
2) Major space in an atom is empty.
3) Atoms nucleus is surrounded by negatively charged particles called electrons.
4) An atom is electrically neutral.
Answer:
6
Explanation:
There is 2 of the coumpond, in one compound, there are 3 oxygens. But when there are two, it is 6.
The answer to this question is False
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