Answer:
1. Define the problem
2. Conduct a literature search
3. Propose a hypothesis
4. Devise an experiment to prove or disprove
5. State conclusions
Explanation: In order to begin an experiment, you must first define a problem or question that you will be answering. Then you must research the problem in order to form a hypothesis, or an educated guess. Then you should devise and execute an experiment to answer your question. The conclusions that you draw will either prove or disprove your hypothesis. Hope this helps!
Answer : Option A) Atomic number of Arsenic is 33.
Explanation : Arsenic contains same number of protons in its atomic nucleus. In arsenic there are 33 protons found in the atomic nucleus. Hence, the atomic number will be 33. It has 5 valence electrons in its outermost shell, which is also called as valence shell. So, its valency becomes 5.
