ATOMS, MOLECULES, AND BASIC CHEMISTRY

Question 1

WHAT IS AN ATOM

Answer 1

Atom: smallest functional unit of matter, atoms bonding together makes molecules
Electrons: negatively charged particles that orbit nucleus
Protons: positively charged particles are part of the nucleus: number of protons are seen on atomic number (bottom number)
Neutrons: neutral particles that are also part of the nucleus: number of protons and neutrons together is part of the atomic mass (top number)

Isotopes: atoms of the same element that have the same number of protons but different number of neutrons. This makes their atomic masses different. They have similar chemical reactions but different nuclear reactions.

Question 2

BONDS

Answer 2

→ covalent bonding: sharing of electrons
→ hydrogen bonding: weak bond involving positive hydrogen and another negative atom, this type of bond is found in DNA.

Question 3

CHEMICAL REACTIONS

Answer 3

– energy is released when bonds are broken, thus meaning when bonds are formed energy is stored within them. Nuclei don’t do anything but switch positions or go into new positions when new bonds are formed. The composition of nuclei does not change, just changed positions.
Combustion reactions: happen when hydrocarbons react with oxygen to form carbon dioxide, water, and heat energy.

Question 3

VAN DER WAALS FORCES

Answer 3

→ Are forces like London dispersion, dipole dipole and hydrogen bonding. It is rapid movement/ vibrations of electrons that cause certain regions to become positive or negative, this causes those regions to be attracted to one another and thus cause bonds, this is one of the reasons why lizards can climb on walls. These interactions/bonds are very weak.

Question 4

PROPERTIES OF WATER

Answer 4

Water is polar because it has dipole dipole forces between the hydrogen and 2 oxygens, this makes water polar, this means only other polar substances can dissolve in water.
Water is often referred to as the universal solvent because water molecules cluster around ions
Non-polar substances will aggregate in water

Amphiphilic: molecules attracted to both polar and nonpolar environments, ex. Phospholipid bilayer.