midterm 5

Question 1

What are the properties of metals? (Section 21-1)

Answer 1

Malleability,
Opacity,
Thermal Conductivity,
Reflectivity,
High melting temperature,
Electrical conductivity

Question 2

Why do metals have their properties? (Section 21-3)

Answer 2

High melting temp: strong bonds between atoms making need for a lot of KE to pull apart to liquid.

Electrical Conductivity: Mobile electrons not bound tight, Charges of the metal move around electrical current.

Thermal Conductivity: electrons responsible for electrical conductivity also carry KE energy which is heat energy.

Malleability: fluid like electrons act like lubricant between nuclei

Opacity: absorb radiation over the entire visible region, as well as infrared and UV.

Reflectivity: mobility of electrons allow them to easily interact with light waves

Question 3

There will be a question about conductivity of ionic compounds (Section 22-4 )

Answer 3

Materials that conduct electricity when dissolved in water are called electrolytes

Question 4

What is an intermolecular force? What is an example of an intermolecular force?

Answer 4

the forces between molecules.
4 types (weak to strong)
-Dispersion, dipole-dipole, hydrogen, covalent.

Question 5

non-metals: atomic volumes, valence electrons, ionization energy

Answer 5

non-metals: small atomic volumes, many valence electrons, and very high ionization energies
metal is opposite

Question 6

There will be a question from Section 22-3 ( I will provide a periodic table of the elements on the test.)

Answer 6

study

Question 7

There is a question on Names of Salts found in section 22-5. How are salts named?

Answer 7

metal first, then non-metal

Question 8

What is the fundamental concept from chapter 23?

Answer 8

covalent bonding: sharing of electrons

Question 9

What is an intermolecular force? What is an example of an intermolecular force?

Answer 9

the forces between molecules.
Intermolecular: between molecules (intra is within)
weak
Inter-molecular forces are forces which mediate interaction between molecules
4 types (weak to strong)
-Dispersion, dipole-dipole, hydrogen, covalent.

Question 10

What fats are liquid at room temperature?

Answer 10

unsaturated fats. oils.

Question 11

What fats are the best and worst for your health in order?

Answer 11

unsaturated
saturated
trans

Question 12

What elements are used to make a silicate ion?

Answer 12

single Si atom surrounded by 4 O atoms

Question 13

There will be a question from Figure 23.7 Relative strengths of molecular interactions.

Answer 13

C6H12O6

Question 14

What is fission?

Answer 14

A nuclear reaction in which an atomic

Question 15

How do scientist know about the different layers of the Earth?

Answer 15

By using half life “T1/2”

time required for 1/2 of the sample to decay

Question 16

Why do saturated and unsaturated fats have different melting temperatures?

Answer 16

Bent: unsaturated fats, kink makes molecule have lower melting/boiling temp.
Straight: saturated fats, high m/b temp.
Shorter the chain, the lower m/b temp

Question 17

There will three questions from table 24.1.

Answer 17

nutrition.poly is better than mono

Question 18

You should know how minerals correspond to type of structure.

Answer 18

294

Question 19

Why do the silicate minerals form different shapes?

Answer 19

morphology

Question 20

What is fusion?

Answer 20

Combining small mass nuclei to make more massive nuclei.

A nuclear reaction in which nuclei combine to form more massive nuclei with the simultaneous release of energy

Question 21

What is fission?

Answer 21

start with very large atoms and split them into smaller atoms.
A nuclear reaction in which an atomic nucleus, especially a heavy nucleus such as an isotope of uranium, splits into two fragments of comparable mass, releasing energy.

Question 22

What is radioactive decay? What are all the types of radioactive decay?

Answer 22

Radioactive decay- changes a nucleus from a high energy state to a lower energy state.
Alpha, Beta, Gamma

Question 23

semiconductors are doped.. youtube

Answer 23

Semiconductors: A solid crystalline substance, such a germanium or silicon, that conducts electricity better than insulators, but not as well as metals. Unlike metals, they become better conductors as their temperature increases.
Doping: inject a foreign substance in order to improve performance

Two Types of Doping:
N-Type: take pure silicon and inject the small amount of an element with five valence electrons - like phosphorus. Brings an extra electron. The semiconductor has more mobile charges - so it conducts current better.
P-Type: an element with only three valence electrons is added to the lass. Like boron. This creates a hole - a place where there should be an electron but there isn’t. This still increases the conductivity of the semiconductor because the electrons can move into it. Hole = lack of an electron. Acts as a positive charge.

*Both dopings are neutral charges

Question 24

What are all the ways to get energy from the nucleus of an atom?

Answer 24

Fission and Fusion.

fission: split big
fusion: combine small

Question 25

Study Figure 25.1 it is the most important figure in all of physical science.

Answer 25

graph thing

Fe is lowest

Question 26

What causes the Earth’s magnetic field?

Answer 26

electric currents in the conductive material of core, created by convection currents due to heat escaping. The Coriolis force, from Earth’s spin, causes swirling whirlpools. This flow of liquid iron generates electric currents, which in turn produce magnetic fields.

Question 27

What are the predominate materials of the Earth’s crust, mantle, and core?

Answer 27

crust: granitic continental crust and basaltic oceanic crust
mantle: peridotite
core: iron

Question 28

Where are the Earth’s most and least dense materials?

Answer 28

Most dense: in middle/core

Least: outside/crust

Question 29

What are the mechanical layers of the Earth?

Answer 29

lithosphere, asthenosphere, mesosphere, outer core, and inner core

Question 30

What are the compositional layers of the Earth?

Answer 30

crust, mantle, core

Question 31

Alpha Decay

Answer 31

helium nucleus emitted from a heavy nucleus,

radioactive decay of an atomic nucleus by emission of an alpha particle

Question 32

Beta Decay

Answer 32

Process that changes neutrons into protons and protons into neutrons.
charge must be conserved.
Radioactive decay of an atomic nucleus accompanied by emission of a beta particle.

Question 33

Gamma Decay

Answer 33

Light.

Photon is emitted when protons and neutrons shift from one energy level to a lower level.