Answer:
Explanation:
Personal opinion/interpretation are usually firsthand explanation to a phenomenon or problem set. They are usually drawn from logical reasoning and deduction about some event. Most times, they are non-scientific in nature in that they are non-methodical and do not rely on the critical thinking precepts scientific studies are hinged on.
Verified observations are usually drawn from carefully planned experiments. From the results of the experiment, critical decisions can be made.
Gay Lussac's Law

Convert:
200°C = 200 + 273 = 473 K
50°C = 50 + 273 = 323 K
Input the value:

Answer:
Volume of the sulfuric acid (25cm³), same mass of each metal (1g)
Explanation:
In an experiment, the CONTROL VARIABLE also known as constant is the variable that is kept unchanged for all groups in an experiment. This is done in order not to influence the outcome of the experiment.
In this case, students are trying to investigate the reactivity of four different metals. They added 1 g of each metal to 25cm³ of sulfuric acid and recorded the temperature change. Based on the explanation of control variable above, the VOLUME OF SULFURIC ACID (25cm³) and the MASS OF EACH METAL (1g) are the CONTROL VARIABLES because they are the same or unchanged in this experiment.