Melissa Collins presents a science video discussing the periodic table's history, organization, and trends. The video covers Mendeleev's creation of the table, the categorization of elements into metals, non-metals, and metalloids, and trends such as reactivity, atomic mass, and density. The video concludes by encouraging viewers to stay curious and explore science further.

Who is credited with the creation of the periodic table?

• Dmitri Mendeleev

• Isaac Newton

• Marie Curie

• Albert Einstein

What was the basis for Mendeleev's organization of the elements?

• Color

• Shape

• Properties

• Size

Which category of elements is located on the left side of the periodic table?

• Non-metals

• Metalloids

• Metals

• Noble gases

What property is shared by non-metals?

• Conductivity

• Luster

• Malleability

• Brittleness

What are elements in the same row of the periodic table called?

• Categories

• Families

• Periods

• Groups

Which family of elements is known for being very reactive and soft?

• Halogens

• Transition metals

• Noble gases

• Alkali metals

What happens to the reactivity of alkali metals as you move down the group?

• Varies randomly

• Stays the same

• Decreases

• Increases

Which element is a liquid at room temperature?

• Mercury

• Gold

• Sodium

• Iron

What trend is observed in atomic mass as you move across and down the periodic table?

• Varies randomly

• Stays the same

• Increases

• Decreases

What does density measure?

• Number of protons

• Volume divided by mass

• Mass divided by volume

• Number of electrons