Using your senses like nose, mouse, hand, ears and others to gather information is called<u> observation.</u> You can get information by feeling, tasting, smelling,hearing and so on.
Earthquakes along the San Andreas fault in California.
<u>Explanation</u>:
- When the two plates collide with each other, earthquakes occur. The contact between them makes this earthquake possible. The contact forces are responsible for the earthquakes as there is contact between two plates.
- The gravitational force is a force that is responsible for elevated tides happening on the east coast or the Jupiter's moons to remain in orbit. But this is not a contact force as there is no contact between them
- Moreover, Without any contact, the magnetic force is a non-contact as it attracts the pins from a distance.
<u>Answer:</u> The Henry's law constant for oxygen gas in water is 
<u>Explanation:</u>
To calculate the molar solubility, we use the equation given by Henry's law, which is:
where,
= Henry's constant = ?
= solubility of oxygen gas = 
= partial pressure of oxygen gas = 2.1 atm
Putting values in above equation, we get:
Hence, the Henry's law constant for oxygen gas in water is
You are right, it's CA Calcium, 40.08, Group 2 and Row 4.
