Drew added yeast and sugar to lukewarm water and placed it in a flask. He stretched a balloon over the opening of the flask. After several minutes, he noticed
small bubbles rising along the side of the flask as the balloon slowly began to inflate.
Drew concluded that -

A)a physical change was occurring

B) the bubbles indicated a chemical change

C) the water surger and yeast were products of a chemical reaction

D) the strong smell was evidence of a physical changer

a mercury barometer is a device that uses the physical properties of mercury in a tube to measure barometric pressure. mercury barometers are used for : -

1. measurement of atmospheric pressure  

2. determining the altitude of a place

3. weather forecasting

4. calibration and checking of aneroid barometers

5. application in fluid mechanics

6. measurement of pressure in aircrafts

7. surface weather analysis

8. preparation of barographs

9. usage in physical sciences like physics, astronomy & chemistry

10. preparation of aircraft altimeters

characteristics of mercury barometer : -

1.used to define and measure atmospheric pressure.

2.on the average at sea level the column of mercury rises to a height of about 760 mm.

3.this quantity is equal to 1 atmosphere.

4.it is also known as standard atmospheric pressure.

5.a barometer in which the weight of a column of mercury in a glass tube with a sealed top is balanced against that of the atmosphere pressing on an exposed cistern of mercury at the base of the mercury column, the height of the column varying with atmospheric pressure.

i think so it’s will be b yes i believe its