Chemistry Unit 7 Exam Nuclear Chemistry

Nuclear/Chemical Reaction: Involves only valence electrons

Chemical

Nuclear/Chemical Reaction: Atoms keep the same identity although they might gain/share/lose electrons and form new substances

Chemical

Nuclear/Chemical Reaction: Occur when nuclei combine, split, and emit radiation

Nuclear

Nuclear/Chemical Reaction: Occur when bonds are broken and formed

Chemical

Nuclear/Chemical Reaction: Temperature, pressure, concentration, and catalysts DO affect reaction rates

Chemical

Nuclear/Chemical Reaction: Large energy changes

Nuclear

Nuclear/Chemical Reaction: Temperature, pressure, concentration, and catalysts DO NOT normally affect reaction rates

Nuclear

Nuclear/Chemical Reaction: Atoms of one element are often converted into atoms of another element

Nuclear

Nuclear/Chemical Reaction: Small energy changes

Chemical

Nuclear/Chemical Reaction: Can involve protons, neutrons, and electrons

Nuclear

Define half-life

Time it takes for a sample to decrease to half its initial amount

Half-life formula

Mf=Mi(1/2)^(t/t1/2)

What elements on the periodic table are always radioactive

Elements with atomic number greater than 83 including actinides (atomic numbers 89-103)

List the type of radiation from lowest to highest penetrating power

alpha, beta, gamma

Alpha particle

4/2 He

Beta particle

0/-1 e or 0/-1 B

Neutron

1/0 n

Positron

0/+1 e

Hydrogen

1/1 H

In fission/fusion reactions, does the product side have bigger/smaller/same mass as the original products

Same

What element is the fuel for the fusion that occurs in the Sun's centrr

Hydrogen

What radiation would be attracted to a positively charged metal

Beta

How do most stars give off energy

Through the proton cycle or carbon cycle

What happens to stars when hydrogen fusion stops

Helium fusion begins

What stages does a star go through to become a black dwarf

Nebula, low/medium mass protostar, red giant, planetary nebula, white dwarf, black dwarf

What stages does a star go through to become a supernovae

Nebula, high mass protostar, high mass star, supergiant, supernova

What do the dark lines in the sun's spectrum indicate about light in those regions

The dark lines are being absorbed by the Sun's atmosphere

Roughly what temperature in Kelvins would indicate a nuclear reaction took place

Very high temperature

The damage produced from ionizing radiation depends on what factors

Type of radiation, energy, type of tissue absorbing radiation, penetrating power, distance from source

What are some benefits of radiation

Medical diagnostic tools like PET or xrays, can destroy cancer cells, detect disease, vitamin D, thermal energy, generate electricity

Life cycle of low mass star

Nebula, protostar, low mass star, red giant, planetary Nebula, white dwarf, black dwarf

What parts of the sun contain iron

Mainly atmosphere, core

Fusion characteristics

Combination of atomic nuclei, responsible for production of heaviest elements-very large amounts of energy, sun powered by fusion, fueled by lightweight isotopes but need high energy to initiate and sustain reaction

Fission characteristics

Splitting of a nucleus into fragments, large release of energy, produces energy/electricity generated by nuclear reactors

Ionizing radiation

Radiation energetic enough to ionize matter with which it collides

Define radiation

Rays and particles emitted by a radioactive source