Answer:

Explanation:
A physical change occurs when only the physical properties change. They are generally reversible and no new substances are formed.
However, in a chemical change, the chemical structures and properties change, plus new substances are formed.
Let's analyze each answer choice.
1. Change in state of matter
The state of matter is a physical property, so this is a physical change.
2. Precipitate was formed
A precipitate is a solid formed in a liquid solution. This is a new substance and a chemical change.
3. Unexpected change in odor.
A change in odor is a sign of chemical change.
4. Formation of bubbles
Bubbles signify the formation of gas or a new substance.
So, the best answer choice is <u>A. change in state of matter</u>
Scientific notation is defined as writing a number between 0 to 10 multiplied by a power of 10
3.5 x 10² x 8.0 x 10⁻²
when we solve the equation
answer - 28
to write in scientific notation the decimal point should come after the first digit from the right. to bring the decimal point from after digit 8 to after digit 2, we have to move one decimal place to the left. then we get 2.8, to get the value as 28 we have to multiply 2.8 by 10
therefore answer is
2.8 x 10¹
The answer is B. light is reflected off the shirt
Answer:
Molarity of a solution that contains 3.11 mol of NaNO3 is 1,24 M
Explanation:
We understand molarity as the number of moles of solute that are contained in 1 L of solution, then if in a solution of 2.50 L we have 3.11 moles, it remains to calculate how many moles do we have in 1 liter.
2,50 L .......... 3,11 moles
1 L .................. x
X = ( 1 L x 3,11 moles) / 2,50 L = 1,24