Astudent measures the range of sound frequencies that the human ear can hear by playing sounds for volunteers between 10 and 30,000 hertz and asking them to raise their hand if they were able to hear it. what type of variable is the independent variable in this experiment? a. categoric b. ordered c. continuous d. discrete

B. Ordered

Explanation:

Categorical Variable: A variable that has two or more categories is known as Categorical Variable. For example, Gender has two categorical variables i.e. Female or Male.

Ordered Variable: It is a categorical variable for which we can order them. For example, the Highest Education Level has variable Elementary School, High School, Some College, College Graduate. Here ordering is possible.

Continuous Variable: It is a variable that can not be count, it can be any value between the range. For example Height, Weight, etc.

Discrete variable: It is countable variable. It can be only certain values. For example Number of absent students in the class, etc.

Here, in the question, it will be ordered variable since here variable is the range of sound between 10 to 30,000 hertz.

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e

a). in this case, dh> 0 and sd> 0. if t becomes larger, the term "-tds" will become more negative. at some point, it is possible that -dts will be more negative than the dh is positive, and the reaction will become spontaneous. this is probably the correct answer, but you should look at all of the other possibilities and make sure of that.