7. which of the following would lower the pitch of a string instrument's sound?

a. adding tension within the string.
b. shortening the effective string length.
c. increasing the thickness of the string used.
d. using less force to vibrate the string.

The correct option is C.

The pitch of a string refers to the quality of sound that is produced by the string when it vibrates. There are three basic factors that affect the quality of pitch of a string, these are: the tension, the thickness of the string and the length of the string. The higher the thickness of the string, the lower the pitch of the string, thus, increasing the thickness of the string will lower the pitch.

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