Chemistry 🧪

What defines an element in chemistry?

A substance made out of atoms that share the same number of protons and cannot be broken down into simpler substances by chemical methods.

What is a compound?

Two or more elements that are chemically bonded together in a fixed proportion.

What are molecules?

Two or more atoms joined by covalent bonds, where they share electrons.

What are positive ions called?

Cations.

What are negative ions called?

Anions.

What describes ionic bonding?

A strong electrostatic attraction between oppositely charged ions, typically between metals and non-metals.

How are elements arranged in the periodic table?

In order of increasing atomic number, with rows as periods and columns as groups.

What does the period number in the periodic table indicate?

The number of electron shells an element has.

What does the group number in the periodic table indicate?

The number of outer shell electrons of an element.

What are noble gases characterized by?

They are stable with full outer shells and are monoatomic and colorless.

What are some uses of noble gases?

Neon is used in signs, Argon in lights, and Helium in balloons.

What is an alloy?

A mixture of two or more metals or a non-metal and a metal.

What does it mean for alkanes to be saturated?

They only have single carbon-carbon bonds and no double bonds.

What state symbol represents a solid?

(s) represents a solid.

Which group in the periodic table is very reactive and why?

Group 1 elements are very reactive due to having only one electron in their outer shells.

What are common air pollutants caused by human activities?

Carbon dioxide, Carbon Monoxide, Methane, Oxides of nitrogen, and Sulfur dioxide.