One type of atomic particle that is found in the nucleus does not contribute to an element's atomic number. What are two characteristics of this type of
atomic particle?

1) They are electrically neutral

2) They have slightly more weight than protons

Explanation:

The given atomic particle found in the nucleus has the following characteristics;

The location of the particle = The nucleus

The (numbers of the) particle does not contribute to (change) the atomic number of the element

The particles found within the nucleus of an atom are; Neutrons and protons

The particle within the nucleus that determines the atomic number = The number of protons

Therefore, the particle referenced in the question is the neutrons

The two characteristics of the neutron are;

1) The neutrons are neutral, electrically

2) Neutrons have slightly more weight than protons

3) Neutrons are magnetic

4) Neutrons are very small

5) Neutrons consist of three quarks; One 'Up', and two 'Down' quarks

Therefore, two characteristics of the particle are;

1) They are electrically neutral and 2) They are slightly heavier than protons.