Jeannie dropped a solid object into a beaker of water and observed it for five minutes. based on her observations, she determined that only a physical change occurred.
which of the following observations would indicate that only a physical change occurred after she added the object?
a.
the object broke apart and seemed to disappear when dropped into the glass of water.
b.
the object sank to the bottom when dropped into the glass of water.
c.
bubbles formed around the object as it sank to the bottom of the water and did not resurface.
d.
the object floated on the top of the water when when dropped into the glass.

*will mark you brainliest + 15 points ** why does the equilibrium of a system shift when the pressure is increased? a. to maximize the stress on the system b. to stop restoring equilibrium to the system c. to increase the total moles of gas in the system d. to decrease the total moles of gas in the system

May someone me with these science questions

These questions are based on the attached photo. the experiment is about burning magnesium metal with oxygen. 1. write the balanced chemical equation for the reaction you are performing. 2. calculate the mass of magnesium metal used in each trial. o trial 1: o trial 2: 3. calculate the actual yield of magnesium oxide for each trial. o trial 1: o trial 2: 4. magnesium is the limiting reactant in this experiment. calculate the theoretical yield of mgo for each trial. o trial 1: o trial 2: 5. determine the percent yield of mgo for your experiment for each trial. o trial 1: o trial 2: 6. determine the average percent yield of mgo for the two trials. your company currently uses a process with a similar cost of materials that has an average percent yield of 91 percent. if the average percent yield of this process is higher than that, this could save the company money. what is your recommendation to the company? support your recommendation using your data, calculations, and understanding of stoichiometry gathered from this lab.