Answer:
WHAT IS THE DEFINITION FOR ISOTOPES
<u><em>the same atomic number (number of protons), but different mass number of neutrons and protons.</em></u>
WHAT ARE EXAMPLES OF ISOTOPES
<em><u>carbon</u></em>
<em><u>nitrogen</u></em>
<em><u>hydrogen</u></em>
WHAT ARE NON EXAMPLES OF ISOTOPES
<u><em>tiger-striped cat</em></u>
<u><em>idk other ones sorry...</em></u>
Cancer is caused by changes (mutations) to the DNA within cells. The DNA inside a cell is packaged into a large number of individual genes, each of which contains a set of instructions telling the cell what functions to perform, as well as how to grow and divide. Errors in the instructions can cause the cell to stop its normal function and may allow a cell to become cancerous.
Answer:
A chemical change is required to separate the elements present in it.
Explanation:
The only true statement from the choices given is that water as a pure substance requires a chemical change to separate the elements present in it.
Water is a molecule consist of two atoms of hydrogen and one atom of oxygen.
- The atoms are covalently bonded together.
- A chemical process, the electrolysis of water is often used to separate the atoms of a water.
- Physical changes cannot be used to separate the atoms of water.
- Water is a compound which consists of two elements.
Therefore, we see that only the first choice satisfies this problem.
Answer: Option (D) is the correct answer.
Explanation:
The chemical reaction equation will be as follows.
This means a new substance has been formed and a chemical change has taken place.
A chemical reaction in which heat energy is absorbed by the reactant molecules is known as an endothermic reaction.
For example, 
On the other hand, a chemical reaction in which heat energy is released by the reactant molecules is known as an exothermic reaction.
For example, 
is an exothermic reaction.
Thus, we can conclude that in the given situation the beaker most likely felt warm because a chemical reaction was producing a new substance.
Number 12 Would Be The Second Answer Because 1+1=2
