The gases that get released form bubbles in the solution
Yasir wanted to study the relationship between sleep and room color. So he has done all the background study required on the topic and arrived at a hypothesis that people fall asleep more rapidly in a room painted in blue color than in a room painted yellow. Yasir inquired several people which color they like better -yellow or blue- and used their feedback to decide whether his hypothesis was correct. There was no experiment conducted to observe the effect of a room color on sleep and the variables to be tested in the experiment were not properly identified.
Therefore, the correct answer would be,
An experiment that directly tests the hypothesis
Variables to be tested by an experiment
a chemical property of iron is the ability to change it, hammer it, roll it, shape it etc
https://quizlet.com/17797282/periodicity-review-flash-cards/
i took a test like this and i went to this site /\ /\ /\ and the flash cards have the answers
