<span>oe is lifting boxes to load a trailer. To follow proper lifting procedures, Joe should:</span>
<u>Answer:</u> This violates the law of constant composition.
<u>Explanation:</u>
Dalton's theory is based on mainly two laws, which are law of conservation of mass and law of constant composition.
Law of constant composition states that a compound always contain the elements in the fixed ratio by their masses.
For Example: In water 
, the hydrogen and oxygen are present in the fixed ratio of 1 : 9 by their mass.
We are given:
A sample of titanium dioxide having 59.95 % of titanium and another sample of titanium dioxide having 60.10 % of titanium.
As, the compound is titanium dioxide. So, the mass percent of titanium must remain the same in both the elements.
Hence, this violates the law of constant composition.
Answer:
D) burning a candle
A demonstration that contains both physical and chemical changes will be BURNING OF A CANDLE.
<em>This is because when a candle is lighted up, on the top of it (where we see flame) the oxygen and other gases present around will be chemically changed (burned up)</em>
<em>When the wax in the top of the candle will get melted due to the heat of the fire a physical change takes places.</em>
The atom that is oxidized : Cr
The oxidizing agent : H₃PO₄
<h3>Further explanation</h3>
Reaction
2 H₃PO₄ (aq) + 2Cr(s) → 2 CrPO₄ (aq) + 3H₂(g)
Atoms undergoing a reduction reaction (decrease in oxidation number) and an oxidation reaction (increase in oxidation number)
H⁺(in H₃PO₄) =+1
H₂=0
Cr = 0
Cr³⁺(in CrPO₄ )
the oxidizing agent.⇒which undergoes a reduction reaction and oxidizes another compound/element : H₃PO₄
