Question 2(multiple choice worth 4 points) (01.01 mc) dominic and eva are using the same type of stopwatches to measure the time it takes for a chemical reaction to occur. they each use the same stopwatch to measure the time. these are their results: person trial 1 dominic 78 seconds eva 81 seconds why are their results unreliable and can lead to a pseudoscientific claim? they did not repeat their tests multiple times. they used the same type of stopwatch. they did not change the reactants in their chemical reactions. only one person should have collected the data.

The correct answer will be option-they did not repeat their tests multiple times.

Explanation:

Pseudoscience or the false science is the scientific practice which is based on the belief system and has no supported evidences.

The pseudoscience facts cannot be verified with the scientific methods which includes the logical questions, hypothesis and results produces through the repeated experiment.

In the given question, Dominic and Eva performed experiments using same stopwatch to note the time of a chemical reaction but they recorded different time period for the same chemical reaction.

This could lead to discrepancies or errors in the results  and formation of conclusion. So experiment must be repeated to avoid the errors which the experimental method lacked.

Thus, the selected option is the correct answer.

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.

it is b that is the answer.