NOTES (kap. 1,1)

Question 1

Atoms are characterized by their atomic number (Z) = number of protons in the nucleus.

Different for each element in the periodic table.

Answer 1

True

Question 2

Do the elements all contain the same number of neutrons?

Answer 2

No, the same element can contain different numbers of neutrons resulting in isotopes.

Question 3

What is the total number of protons and neutrons called?

Answer 3

Nucleon number/mass number, and is responsible for most of the mass of the atom.

Question 4

What space does the electrons occupy the nucleus?

Answer 4

They occupy in atomic orbitals.

Question 5

How do ions form?

Answer 5

When an atom loses or gains an electron. (cation = Na+, anion = Cl-).

Question 6

Atoms can interfere in different ways to form various materials:

Atoms share one or more electrons in a delocalized sea of electrons (forming metallic bonds) = metals.

Ionic bonds (attraction of anions and cations) = form salts

Atoms connecting through covalent bonds = form molecules.

Answer 6

True.

Question 7

Can molecules vary?

Answer 7

Yes, all the way from water, to proteins and DNA:

Question 8

What properties are crucial for molecules?

Answer 8

Covalent bonds are crucial, hoewever weaker non bonding covalent interactions (Van der waals and hydrogen bonds etc) can play a significant role:

1) influence the state of matter

2) influence the form, shape, stability.

3) influence the function of the molecule we encounter.