Question

Two unknown household items are tested with litmus paper. Substance A changes red litmus paper to blue, while Substance B changes blue litmus paper to red. Which of the following most accurately explains the results of the experiment? (1 point)

Substance A is an acid and Substance B is a base.

Both Substances A and B are acids.

Substance A is a base and Substance B is an acid.

Both Substances A and B are bases.

Answer 1

The correct explanation for the results of the experiment is:

**Substance A is a base and Substance B is an acid.**

This is because a base turns red litmus paper blue, indicating that it has a pH greater than 7, while an acid turns blue litmus paper red, indicating that it has a pH less than 7.

Answer 2

Amos is using three different colors of candy to create atomic models. He constructs a model of an oxygen atom as demonstrated.

proton:8

neutron 10

electron 10

Amos wants to modify this model to represent a different isotope of oxygen. What adjustments could he make to achieve this
Otake away two blue candies

add one red candy

add one green candy

rearrange the blue candies

Answer 3

To represent a different isotope of oxygen, Amos needs to adjust the number of neutrons in his model, since isotopes of an element differ in the number of neutrons but have the same number of protons and electrons.

In the initial model, Amos has:

- Protons: 8
- Neutrons: 10
- Electrons: 10

To create a different isotope of oxygen, he could:

- Take away two blue candies (assuming blue represents neutrons), which would reduce the number of neutrons from 10 to 8.

This would create an isotope of oxygen with 8 neutrons, which is a different isotope of oxygen (specifically, it would represent the most common stable isotope of oxygen, oxygen-16).

So, the correct adjustment to achieve a different isotope of oxygen would be:

**Take away two blue candies.**