Answer: Burning changes the chemical make up of an object.
Explanation:
A chemical change can be defined as a change in the substance when it combines with other kind of substance to form a new substance. A chemical change can also occur when a substance is broken down into two or more products. These changes cannot be reversed. These changes affect the physical make up of an object. For example, burning as when an object is burned it cannot be transformed into its original form. A wood if burned can be converted into ash, water and carbon dioxide cannot regain its original form after burning so burning brings about chemical change in an object.
Answer: b) Less dense
Explanation:
Differences in density is one reason objects float or sink.
An object more dense than the fluid in which it is immersed will sink, while objects less dense than the fluid in which it is immersed will float to the surface.
But objects floats at constant level if the density is equal to the density of the fluid in which it is immersed; it neither rises nor sinks in the fluid in this case.
(1) 14C also known as Carbon-14, is used to radio-date organic materials as well as earth materials.
Answer:
The answer to your question is: Neutral
Explanation:
A neutral solution is a solution whose pH is 7.
That means that this solution has the same amount of H⁺ and OH⁻.
Examples of neutral solutions:
- distilled water
- sugar solution
- table salt
- cooking oil.
Answer:
C. To determine how efficient reactions are.
D. To determine how much reactant they need.
Explanation:
When you are doing a reaction, you are hoping for a percent yield to close of 100%. You make the reaction and determine how many product you obtain. If you know the percent yield of a reaction you can calculate the amount of reactant you need to obtain a determined amount of product.
Having this in mind:
A. To balance the reaction equation. false. To calculate percent yield you need to balance the reaction before. You don't use percent yield to balance the reaction
B. To determine how much product they will need. false. You determine how much product you obtain after the reaction. How much product you need is independent of percent yield
C. To determine how efficient reactions are. true. A way to determine efficience of a reaction is with percent yield. An efficient reaction has a high percent yield.
D. To determine how much reactant they need. true. If you know percent yield of a reaction you can know how many reactant you must add to obtain the amount of product you want.
