Chemistry quiz 1

Question 1

What do we call the smallest unit that retains the properties of a given element?

Answer 1

Atom

Question 2

Name the 3 subatomic particles. What is the electrical charge of each? What is the atomic mass/weight of each?

Answer 2

Protons: positive charge, 1 mass unit
Neutrons: neutral charge, 1 mass unit
Electrons: negative charge, insignificant mass unit

Question 3

A;; atoms of a given element have the same atomic number, this is determined by the number of ___________

Answer 3

Protons

Question 4

The atomic weight/mass of an element is the sum of

Answer 4

Protons + Neutrons

Question 5

If an atom has 6 protons, it is a carbon atom. If it has an atomic mass of 12, how many neutrons does it have in the nucleus?

Answer 5

6 neutrons

12 mass- 6 protons (atomic #) = 6 neutrons

Question 6

If another atom has 6 protons but 7 neutrons, what element is it? What is its atomic mass?

Answer 6

Carbon atom, its an isotope of Carbon

Atomic mass is now 13.

Question 7

What is an isotope?

Answer 7

Atoms which contain the same number of protons but a different number of neutrons

Question 8

Which electrons participate in chemical bonding?

Answer 8

Valence electrons (electrons on the outer shell)

Question 9

If an atoms atomic number is 12, how many electrons would it like to receive in order to fill its outer shell?

Answer 9

It has 2 in the outer shell, this atom needs 6 more electrons to fill the outer shell

Question 10

What is a charged atom called? If its positive? If its negative?

Answer 10

Positive charged atom = cation

Negative charged atom = anion

Question 11

In what type of bonding are electrons shared? Transferred/ taken?

Answer 11

Shared = covalent bond

Transferred/ taken = ionic bond

Question 12

What makes water polar?

Answer 12

Electrons are unequally shared between atoms.
The shared electrons spend more time on the O atom then they do on the H atoms.
Negative O, Positive H

Question 13

What is an electrolyte? Name 3 very common ones

Answer 13

Charged particles that are dissolved in H20
K+
Na+
Cl-

Question 14

What type of reaction occurs when two or more small molecules are bonded together

Answer 14

Synthesis

Dehydration synthesis, removal of water

Question 15

What type of reaction occurs when a large molecule is broken into smaller pieces by breaking bonds and releasing energy?

Answer 15

Decomposition

Hydrolysis

Question 16

A substance made up of one kind of atom is a/an

Answer 16

Molecule

Question 17

A substance composed of different kinds of atoms bonded together is a/an

Answer 17

Compound