Answer:
Forces between similar molecules are said to be <em>cohesive</em> while those between different types of molecules are said to be <em>adhesive</em>.
Water 'beads' due to its strong <em>cohesive</em> forces. The meniscus of water in a glass tube is <em>concave</em> because the <em>adhesive</em> forces are strong.
Explanation:
The water in a tube has stronger adhesive forces between the water and glass molecules, so the cohesive forces between water molecules are weaker. That makes the water 'ascend' through the tube, giving a concave form of the meniscus. Another example is mercury, which is the opposite. In this case, the cohesive forces are stronger than the adhesive ones, thus the meniscus is convex.
Answer:
Explanation:
A single replacement or single displacement reaction is a reaction in which one substance replaces another.
A + BC → AC + B
The replacement of an ion in solution by a metal higher in the activity series is a special example of this reaction type.
The relative positions of the elements in the activity series provides the driving force for single displacement reactions.
A double replacement reaction is one in which there is an actual exchange of partners between reacting species. This reaction is more common between ionic substances;
AB + CD → AC + BD
Such reactions are usually driven by;
- formation of precipitation
- formation of water and a gaseous product
Answer:
2. Na2O
Reasoning:
Na (soduim) is the only metal out of all the elements in the answer choices, and is bonded with oxygen, a nonmetal, therefore creating an ionic bond.
