Chem. Exam 1

Question 1

Nuclide is characterized by

Answer 1

protons or atomic #
# neutrons
mass # (#p + #n)

Question 2

Isotopes

Answer 2

Nuclides of same elements w/ same diff. # neutrons (or diff. mass #s)

Question 3

Isotopes of Hydrogen & they’re components

Answer 3

Protium (1 p & 0 n) (99.985 %)
Deuterium (1 p & 1 n) (0.015%)
Tritium (1 p & 2 n) (radioactive)

Question 4

Isotopes of Carbon & they’re components

Answer 4

C12: (6 p & 6 n) (98.89%)
C13: (6 p & 7 n) (1.11%)
C14: (6 p & 8 n) (radioactive)

Question 5

Chemical Formula

Answer 5

Diff. atoms combine to form compounds where subscripts indicate relative # of atoms present

Question 6

Chemical Bonds

Answer 6

How atoms are connected together but vary from compound to compound

Question 7

Covalent Bonding

Answer 7

sharing of e- to hold atoms in molecules together

Question 8

Ionic Bonding

Answer 8

e- are completely transferred from on atom to another
- usually involves metal and nonmetal
- attraction between cation (+) & anion (-)
- results in formation of ions

Question 9

Ion

Answer 9

charged atom

Question 10

Non-directional bond & ex.

Answer 10

Ionic: has interactions w/ many diff. ions resulting in ionic solid (ex. salt)

Question 11

Isotropic

Answer 11

finds anything around them that isn’t oppositely charged

Question 12

Modern Periodic Table vs Mendeleev

Answer 12

Modern: links together families of elements that have similar chemical or physical composition
Mendeleev: based on atomic masses of elements

Question 13

Eight Groups of Main Group Elements

Answer 13

1. Alkali Metals
2. Alkaline Earth Metals
3. Boron family (teriels)
4. Carbon family (tetrels)
5. Nitrogen group (pnictogens)
6. Chalcogens
7. halogens
8. Noble gases

Question 14

part of atom that determines its chemistry

Answer 14

e- in an atom

Question 15

Actinides

Answer 15

most produced artificially (except uranium and thorium have reasonable natural occurrence)

Question 16

Core e-

Answer 16

Aren’t usually available for bonding (exception is group 1B) (Ag, Cu, & Au may have valences of 1,2, or 3)

Question 17

Characteristics of Metals

Answer 17

Malleable (hammered into sheet)
Ductile (drawn into wire)
Luster (shinyness)
Good conductor of heat & electricity

Question 18

Characteristics of Non-Metals

Answer 18

Brittle
Dull color
Bad conductor of heat & electricity

Question 19

Semimetals/Metalloids

Answer 19

have characteristics that resemble metals in some regards and nonmetals in others

Question 20

Sides of periodic table & which is metallic

Answer 20

Left: metalic
Right: nonmetalic

Question 21

Hydrogen facts

Answer 21

• most abundant element on earth
• flammable
• lighter than oxygen so it floats

Question 22

Helium facts

Answer 22

• 2nd most abundant element
• non-flammable
• lighter than oxygen so it floats
• used in cytogenetics & MRI

Question 23

Alkali Metal (what happens when it combines w/ water?; are they soft or hard?; are they malleable & ductile?; are they reactive toward water?)

Answer 23

• combines with water to form alkaline solutions
• soft (can be cut w/ a knife)
• malleable & ductile (ex. sodium wire)
• HIGHLY reactive towards water

Question 24

Alkali Earth Metals (hardness & reactivity)

Answer 24

• harder the alkali metals
• less reactive then alkali metals

Question 25

Meaning of EARTH is alkali earth metals

Answer 25

substances that are insoluble in water & stable to heat (oxides of these elements)

Question 26

Magnesium reactivity w/ water vs steam vs burning in CO2

Answer 26

Water: slow
Steam: quickly to form magnesium hydroxide
CO2: creates magnesium oxide & carbon

Question 27

How fire extinguishers work

Answer 27

displace oxygen (feeds fire) with CO2

Question 28

Most toxic element

Answer 28

Tl

Question 29

Boron group

Answer 29

• transition from semimetallic to metalic
• all form TRIVALENT compound 1:3 EXCEPT (idiom & thallium which form monovalent compounds 1:1) (inert pair effect)

Question 30

Inert Pain effect

Answer 30

Reluctance of valence electrons to participate in bonding
- lone pair becomes more stable for heavy elements