2. Atoms & Elements

How many neutrons are present in a neutral atom of beryllium-9?

In a neutral atom, how many principal energy levels (shells) are possible according to the quantum mechanical model?

Which of the following atoms is NOT a component of a water molecule?

Why are atoms electrically neutral under normal conditions?

Which of the following best describes the composition of cathode rays?

Which of the following primarily determines the chemical properties of an element?

Which element is the heaviest (has the highest atomic number) that can be formed by fusion in the core of massive stars before supernova?

Which property determines the identity of an atom?

Which of the following substances is composed of only one type of atom?

When two hydrogen atoms combine with one oxygen atom, the result is a water molecule, which is a(n):

An atom has a mass number of 210 and an atomic number of 85. How many neutrons does this atom have?

Which subatomic particle determines the identity of an element?

In a water molecule (H₂O), which atom carries a partial negative charge?

Which part of an atom contains the protons and neutrons?

How many protons are present in an atom with an atomic number of 23 and a mass number of 51?