Answer is ₂₀⁴²Ca.<span>
In AZX notation
A<span> - Represents the </span>mass number of atom.
Mass number = number of
protons + number of neutrons.
<span> It is shown at
the </span>above of the left side<span> of the
atom.</span>
<span> Here it is </span>42.
<span> </span>Z - Represents the atomic number.<span>
Atomic number = number of protons.
</span><span>It is shown at the</span> bottom line of the left side of the atom.<span>
</span>Here it is 20.<span>
X - </span>Represents the symbol of the atom.<span>
<span> </span></span>Here</span> X is Ca.<span>
</span>
Answer:
The plastic wrap of the covered cup acts like the atmosphere, and traps the water vapor. In a real cloud, the water vapor cools back into liquid water. In the covered cup, the air can only hold so much vapor, and the vapor condenses back to liquid water forming a “rain cloud” on the plastic wrap.
Explanation:
When two element combine to form more than one compound i hope this helps you with work have a nice day :)
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:
1.047 M
Explanation:
The given reaction:

For dichromate :
Molarity = 0.254 M
Volume = 15.8 mL
The conversion of mL to L is shown below:
1 mL = 10⁻³ L
Thus, volume = 15.8 ×10⁻³ L
Thus, moles of dichromate :

Moles of dichromate = 0.0040132 moles
1 mole of dichromate react with 6 moles of iron(II) solution
Thus,
0.0040132 moles of dichromate react with 6 × 0.0040132 moles of iron(II) solution
Moles of iron(II) solution = 0.02408 moles
Volume = 23 mL = 0.023 L
Considering:

<u>Molarity = 0.02408 / 0.023 = 1.047 M</u>