2. Atoms & Elements

How many neutrons are present in the nucleus of a sodium atom with a mass number of 23?

The most abundant element in the atmosphere can also be found in which of the following?

Where are positively charged particles, known as protons, found in an atom?

Which of the following are the very small particles that make up matter?

Which property of an atom determines the identity of an element?

How many neutrons are present in an atom of copper (Cu) with atomic number 29 and mass number 63? Round your answer to the nearest whole number.

Which of the following is the number of protons in a platinum (Pt) atom?

Which subatomic particle carries a negative charge and orbits the nucleus of an atom?

The superscript preceding each hydrogen atomic symbol (H) represents which of the following?

Which of the following is the fundamental building block of all matter?

Which property of an atom determines the identity of a chemical element?

Where are the reactive electrons of an atom typically located?

In what chemical form is carbon most commonly found in Earth's atmosphere?

Which planet in our solar system is believed to have helium rain in its interior?

Which of the following best describes the current composition of Earth's atmosphere by volume?