Eddie experimented to find out which freezes at a lower temperature, distilled water or salt water. The steps he used in his experiment are shown below. 1Fill one beaker with 250 mL of room-temperature distilled water

2Fill another beaker with 250 mL of room-temperature salt water

3Measure the mass of the liquid in both beakers

4Place both beakers in a freezer

Observe the temperature at which the liquids freeze

Which of the steps in Eddie's experiment was NOT needed?
A.4
B.2
C.3
D.1

the answer is C. 3. measure the mass of the liquid in both beakers

why do the isotopes of a particular element behave differently in nuclear reactions but the same in chemical reactions? chemical reactions involve changes to electrons in an atom; isotopes do not differ in electrons, and so they react the same way during chemical changes.

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance