The electron cloud model describes which of the following?
the negative charge of the electron
the trails left by an electron as it moves around the nucleus
the group of protons that are in the nucleus
the neutron orbital
2nd question:
if an oxygen atom has 8 protons and 10 neutrons in its nucleus, what is its atomic number?
18
10
8
not enough information to calculate
3rd question:
if an atom loses a neutron, what happens?
its mass stays the same, and it becomes a different element.
its mass stays the same, and it is still the same element.
its mass is lowered, and it becomes a different element.
its mass is lowered, but it is still the same element.

1.B.The trials left by an electron as it moves around the nucleus .

2.8

3.Its mass is lowered, but it is still the same element.

Explanation:

1.Electron cloud model: It says  that  we cannot know exactly where an electron is at any given time, but the electrons are more likely to be in specific areas.The electron model says that electron have no fixed position so, it traces their path.

Therefore, the trials left by an electron as it moves around the nucleus .

Option B is true.

2.We are given that

Number of protons=8

Number of neutrons=10

We have to  find the atomic number

We know that atomic number=Number of protons=8

Hence, atomic number of oxygen=8

3.When an atom loses a neutron then mass decreases but the element does not change.Because when mass number different and atomic number are same then the element are called isotopes of an element.In isotopes , neutron numbers  are different.

If an atom loses an neutron then atomic number remain same  and element remain same.

Its mass is lowered, but it is still the same element.