Phase transition is when a substance changes from a solid, liquid, or gas state to a different state. Every element and substance can transition from one phase to another at a specific combination of temperature and pressure.
<em>Answer:</em>
<em>B.) A hot liquid or air that expands, becomes less dense, and rises or becomes more dense and sinks.</em>
<em>Explanation:</em>
<em>Convention is the movement caused within a fluid by the tendency of hotter and therefore less dense material to rise, and colder, denser material to sink under the influence of gravity, which consequently results in transfer of heat.</em>
Answer:
Option D. Activation energy
Explanation:
Activation energy is the minimum energy required to start a chemical reaction. For a reaction to occur, the reactants must possess energy equal or greater than the activation energy else the reaction will not occur.
Answer:
See explanation
Explanation:
From left to right, the oxides across period 3;
i) Period 3 oxides all appear white in colour. They are all crystalline solids and their melting points decrease from left to right.
ii) The volatility of period 3 oxides increases from left to right across the periodic table
iii) The metallic oxides on the right hand side adopt giant ionic structures. Silicon oxide which is in the middle of the period forms a giant covalent structure. Oxides of other elements towards the right hand side form molecular oxide structures.
iv) The acidity of oxides of period 3 increases from left to right. Metals on the left hand side form basic oxides while non-metals on the right hand side form acidic oxides. The oxide of aluminium in the middle is amphoteric.
v) The oxides of period 3 elements do not conduct electricity. However, the metallic oxides on the lefthand side conduct electricity in molten state. The non-metallic oxides on the right hand side are molecular hence they do not conduct electricity under any circumstance.
