Answer:
a) Measurements have a good precision.
Explanation:
Accuracy is the proximity of the data to the value considered as real, in this situation we do not know the real value and we do not know if the data is accurate or not, so we can discard options b and d.
Now, precision is the proximity of the data obtained among themselves and that is what we can observe, so the appropriate answer is the option a.
Answer:
Mass = 182.4 g
Explanation:
Given data:
Number of moles of Al₂O₃ = 3.80 mol
Mass of oxygen required = ?
Solution:
Chemical equation:
4Al + 3O₂ → 2Al₂O₃
Now we will compare the moles of aluminum oxide and oxygen.
Al₂O₃ : O₂
2 : 3
3.80 : 3/2×3.80 = 5.7
Mass of oxygen:
Mass = number of moles × molar mass
Mass = 5.7 mol × 32 g/mol
Mass = 182.4 g
<h3><u>Answer;</u></h3>
Find the number of 1-foot cubes that fill the fish tank
<h3><u>Explanation;</u></h3>
Volume of a cuboid such as the fish tank is given by the product of length width and height;
Such that; Volume = length × width × height
Similarly, we can count the number of 1 foot cube that can fill the fish tank.
And since each cube has a volume of 1 cubic ft, then the number of cubes will be equivalent to the volume of the fish tank in cubic ft.
There are 30 protons and 39 neutrons in the nucleus.
This must me the isotope of an element with an atomic mass close to 69 u.
The only candidates are Zn and Ga.
Zn has a zinc-69 isotope with mass 68.926 u.
Ga has a gallium -69 isotope with mass 68.925 u.
The isotope is probably
.
It has 30 protons and 39 neutrons.
this is the answer is
Zn<span> + </span>HCl<span> = </span>ZnCl2<span> + </span>H2 <span> </span>
