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