. A scientist placed a sample of lithium into a container of water. The scientist observed the lithium floating and making a buzzing sound as gas bubbles were forming around it. Which conclusion is BEST supported by this observation

The conclusion that best support the observation is that (A CHEMICAL CHANGE took place).

Explanation:

A chemical reaction is defined as the process by which two or more substances, which are often referred to as REACTANTS, combine through bond formation or dissociation of bonds to form new PRODUCTS. In this type of reaction, a CHEMICAL CHANGE occurred because a new substance is formed as a result of the chemical reaction that took place.

There are different characteristics of a reaction which shows that a chemical change has occurred, these includes:

--> Color Change

--> Production of an odor

--> Change of Temperature

--> Evolution of a gas (formation of bubbles)

-- Precipitate (formation of a solid)

From the chemical reaction in the given question, Lithium metals reacts slowly with water to form a colourless solution of lithium hydroxide (LiOH) and hydrogen gas (H2). Here we observe that the buzzing sound of formed gas bubbles shows that a gas was given off. Therefore in conclusion, a CHEMICAL CHANGE took place.

d: the voltage of the secondary coil is less than that of the primary coil.

im not suree sorry if wrong

i just calculated it all out, and not including weekends, and all the different days off. as of this school year (2018-2019) students are spending 2198 hours in school this year