Chemistry Of Life Ch 2

Question 1

What is a valence?

Answer 1

The outer energy shell of an atom, it has incomplete orbitals.

Question 2

What are valence electrons?

Answer 2

The number of unpaired electrons in the valence.

Question 3

Why do valence electrons matter?

Answer 3

They let you know how many covalent bonds an atom can make.

Question 4

How many valence electrons does Hydrogen have?

Answer 4

1

Question 5

How many valence electrons does Oxygen have?

Answer 5

2

Question 6

How many valence electrons does Nitrogen have?

Answer 6

3

Question 7

How many valence electrons does Carbon have?

Answer 7

4

Question 8

What is an Ion?

Answer 8

A charged atom

Question 9

What is Anion?

Answer 9

A negatively charged atom

Question 10

What is a Cation?

Answer 10

A positively charged atom

Question 11

Are Covalent or Ionic bonds stronger?

Answer 11

Covalent

Question 12

What is a Covalent bond?

Answer 12

A bond where atoms are sharing one or more electrons.

Question 13

What is an Ion bond?

Answer 13

A bond between atoms due to their electronegativity.

Question 14

How does an Ion bond form?

Answer 14

When atoms gain and/or lose electrons.

Question 15

What is a salt?

Answer 15

An ionic bond.

Question 16

What is the weakest, between the Covalent, Hydrogen, and Ionic bonds?

Answer 16

Hydrogen bonds

Question 17

What is a Hydrogen bond?

Answer 17

A bond between positive and negative polars. Normally something negative being attracted to Hydrogen, but not always.

Question 18

What does it mean to be hydrophilic?

Answer 18

Loves water, is polar and forms Hydrogen bonds.

Question 19

What does it mean to be hydrophobic?

Answer 19

Hates water, is non polar and instead of forming a hydrogen bond, it dissolves. Like salts.

Question 20

How many Hydrogen bonds can a water molecule make?

Answer 20

4, in the form of ice.

Question 21

What is a hydration shell?

Answer 21

A shell that forms when water disrupts Ionic bonds and takes the place of the former bond.

Question 22

Why is water attracted to other atoms?

Answer 22

Because it is polar.

Question 23

What is the smallest unit of matter that retains its characteristics?

Answer 23

Atom

Question 24

What is an atom made of?

Answer 24

Protons (+), Neutrons (0), and Electrons (-).

Question 25

What is in the atoms nucleus?

Answer 25

Protons and Neutrons.

Question 26

What is an energy shell?

Answer 26

The location of electrons.

Question 27

What is the "house" that holds electrons?

Answer 27

Orbitals.

Question 28

How many electrons can one orbital hold?

Answer 28

2 electrons

Question 29

How many orbitals are in the first energy shell?

Answer 29

1

Question 30

How many orbitals are in the second (and all consecutive) energy shells?

Answer 30

4 orbitals

Question 31

What is the Atomic number of an atom?

Answer 31

The number of protons it has.

Question 32

What does it mean for an atom to be neutral?

Answer 32

It has an equal number of protons and electrons.

Question 33

What is the Atomic mass?

Answer 33

Number of protons plus the number of neutrons.

Question 34

How can you find the number of protons an atom has?

Answer 34

Atomic mass minus atomic number.

Question 35

What are Isotopes?

Answer 35

Any variation of an atom that has more neutrons than its basic atom does. Like Carbon 14 it is still Carbon, because it has 6 protons, but it has more than 6 neutrons, it has 8.

Question 36

What is an element?

Answer 36

A substance that cannot be broken down to other substances by chemical reactions.

Question 37

What are trace elements?

Answer 37

Elements required by organisms, but only in minute quantities.

Question 38

What is a radioactive isotope?

Answer 38

One in which the nucleus decays spontaneously.

Question 39

What does it mean to be polar?

Answer 39

It means the atoms in an element are unbalanced in electronegativity, and so the shared electron spends more of its time around one atom than the other.

Question 40

What does it mean to be on polar?

Answer 40

It means the atoms in an element are equal in there electronegativity and the shared electron spends an equal amount of time around each atom.

Question 41

Is H2O polar or non polar?

Answer 41

Polar

Question 42

What kind of bond makes up a water molecule?

Answer 42

Polar Covalent bonds.

Question 43

What does salt do to Hydrogen bonds?

Answer 43

It breaks them up.

Question 44

What type of molecule is | C-C-C-C-C-C=O?

Answer 44

Sugar

Question 45

What type of bond is H & C?

Answer 45

Non polar, Covalent. (Methane)

Question 46

What type of bond is H &I O?

Answer 46

Polar, Covalent bond (Water)

Question 47

What type of bond is Na & Cl?

Answer 47

Ionic bond (Table Salt)

Question 48

How does an atom become positively charged and what does that mean?

Answer 48

It loses an electron, which means it has one more proton than electron.

Question 49

How does an atom become negatively charged, and what does that mean?

Answer 49

It gains an electron and has one more electron than proton.

Question 50

How do you indicate negative and positive charges with atoms?

Answer 50

1- means 1 extra electron. 2- means 2 extra electrons. 1+ means 1 extra proton. 2+ means 2 extra protons.

Question 51

What is the shape of a molecule that has two atoms?

Answer 51

Linear.

Question 52

What is the shape of a molecule with three atoms?

Answer 52

A rough V

Question 53

What is the shape of a molecule with 4 atoms?

Answer 53

A tetrahedron (squat diamond)

Question 54

Atoms with the same # of protons but with different electrical charges are?

Answer 54

Different Ions

Question 55

In the following molecule, what atom will have the strongest partial positive charge? ``` O // H C - O-H / / N - C-H / / H R ```

Answer 55

The C atom that is attached to the O's because it is bound to the two most electronegative atoms, which are both pulling electrons from C

Question 56

When Chemists and Biologists want to show how atoms are bonded in a molecule what do they use?

Answer 56

A structural formula