The smallest particle of an element.
What is an atom.
This scientist created the first widely accepted periodic table.
Who is Dmitri Mendeleev.
The symbol for oxygen.
What is O.
I am added to pools to help kill germs.
What is chlorine.
The lightest element on the periodic table.
What is hydrogen.
Atoms are made of these three main types of particles.
What are protons, neutrons, and electrons.
The horizontal rows on the periodic table are called these.
What are periods.
The symbol for gold.
What is Au.
I make up about 78% of Earth's atmosphere.
What is nitrogen.
The element used in balloons because it is lighter than air and nonflammable.
What is helium.
This particle has a negative charge.
What is an electron?
The vertical columns on the periodic table are called these.
What are groups or families.
This element makes up most of the air we breathe.
What is nitrogen.
I am the basis of all known life.
What is carbon.
This element is essential for strong bones and teeth.
What is calcium.
This particle has no charge.
What is a neutron.
Elements in the same group usually have similar ______.
What are properties.
This element has the symbol Na.
What is sodium.
Without me, most modern computer chips would not exist.
What is silicon.
Diamonds are made almost entirely from this element.
What is carbon.
The center of an atom where protons and neutrons are found.
What is the nucleus.
The periodic table is arranged by increasing ______ number.
What is atomic.
This element is liquid at room temperature and has the symbol Hg.
What is mercury.
My chemical symbol is different from my English name because it comes from the Latin word natrium.
What is sodium.
This letter of the alphabet does not appear in any official chemical symbol on the periodic table.
What is J.