As Nuclear Physics Flashcards
What was fired at the gold foil in the Geiger-Marsden experiment?
alpha (α) particles
What did most alpha particles do?
Passed through the foil
What did a few alpha particles do?
Deflected at large angles or bounced back
What was concluded about the atom from this experiment?
Most of the atom is empty space, and the nucleus is small, dense, and positively charged
What is the nucleon number (A)?
The total number of protons and neutrons
What is the proton number (Z)?
The number of protons in the nucleus
What is an isotope?
Atoms of the same element with different numbers of neutrons
What is the simple model of an atom?
A nucleus made of protons and neutrons with electrons moving around it
What quantities are conserved in a nuclear process?
Nucleon number, proton number, and mass-energy
What does it mean that radioactive decay is random?
It is impossible to predict when a nucleus will decay
What does it mean that radioactive decay is spontaneous?
It is not affected by temperature, pressure, or other external factors
What is an alpha (α) particle?
A helium nucleus with 2 protons and 2 neutron
What is a beta (β) particle?
A fast-moving electron (β⁻) or positron (β⁺)
What is a gamma (γ) ray?
Electromagnetic radiation with no charge or mass
Which radiation has the highest ionizing power?
Alpha (α)
Which radiation is the most penetrating?
Gamma (γ)
What happens in alpha (α) decay?
The nucleus loses 2 protons and 2 neutrons
What happens in beta-minus (β⁻) decay?
A neutron turns into a proton, and an electron is emitted
What happens in beta-plus (β⁺) decay?
A proton turns into a neutron, and a positron is emitted
What happens in gamma (γ) decay?
The nucleus releases energy without losing particles
What is a fundamental particle?
A particle that cannot be broken down into smaller parts
Are protons and neutrons fundamental particles?
No, they are made of quarks
What are the two main quarks in protons and neutrons?
Up (u) and Down (d) quarks
What is the charge of an up quark?
+2/3 e
