Answer:
The correct balanced equation is: 4Al + 3O₂ ➞ 2Al₂O₃
Explanation:
Unfortunately, that isn't the balanced equation. If you take the original equation [unbalanced],
Al + O₂ ➞ Al₂O₃
We have 1 aluminium and 2 oxygen on the left-hand side. On the right-hand side, we have 2 aluminium and 3 oxygen. So we must add 3 on the oxygen in the left-hand side and 2 on the aluminium oxide in the right-hand side.
Al + 3O₂ ➞ 2Al₂O₃
Now if you check, we have 1 aluminium and 6 oxygen on the left-hand side and 4 aluminium and 6 oxygen on the right-hand side. The number of moles of oxygen is equal but the number of moles of aluminium isn't. So we must add 4 on the aluminium of the left-hand, in order to have a balanced equation.
4Al + 3O₂ ➞ 2Al₂O₃
Question: The greater the mass of an object is, the more ___________ is needed to move it.
Answer: B. Force
1) There must not be credible contrary evidence to the ideas suggested by the theory.
2) The models and theories must obey the already established laws of physics. Laws are theories which have such an overwhelming amount of evidence that they are universa, and cannot be disproven.
Answer:
e. none of these
Explanation:
An object in FREE-FALL on the MOON would experience only acceleration
Answer:
Explanation:
Edit to add part a
a) Heating a gas causes the atoms to increase their kinetic energy. With only atmospheric pressure to contain it, the gas will decrease in density by pushing colder gas out of the way. The lid is then sealed to the jar and allowed to cool. The cooling gas, now constrained by the volume of the jar will be forced to lower its pressure to maintain equilibrium. The lower pressure inside the jar will allow the atmospheric pressure outside the jar to "click" the lid indicating a proper seal.
b Before opening there is a much lower pressure inside the jar than outside. The outside pressure keeps the lid constantly in the "clicked" position.
c After the jar is opened, the pressure on either side of the lid is equal and an unbalanced force applied to one side of the lid or the other can cause the lid to "click" or "unclick" depending on the initial position.