Atomic numbers Flashcards
What is a protons position, charge and relative mass?
Nucleus, +1, 1
What is a electrons position, charge and relative mass?
around nucleus, -1, negligible
What is a neutrons position, charge and relative mass?
nucleus, 0, 1
What is a mass number
the total number of particles in the nucleus
How to identify the mass number
no. of protons + no. of neutrons or the top of number on periodic table
where can the number of neutrons in an atom be found?
= mass number - atomic number
top number - bottom number
Where is the atomic number, protons and electrons found?
bottom of number on periodic table
What is an isotope?
atoms which contain different numbers of neutrons in the nucleus.
What is a radioactive isotope?
A radioisotope is an atom with an unstable nucleus that decays and emits radiation until the nucleus becomes stable.
How do you tell what element is more delta positive or negative
further to right = more negative as electronegativity increases as you move across the periodic table from left to right
What is direct radiation damage?
occurs when alpha or beta particles actually collide with cell molecules causing them to break.
What are two potential consequences of direct radiation?
if there is a lot of damage the cell cannot repair itself and dies
if radiation damages DNA, then mutations can occur when the cell divides and this could lead to the development of cancer.
What is indirect radiation damage?
Occurs when the high-energy radiation emitted from the nucleus strips electrons from atoms/molecules as it passes close by and creates charged particles or ions within the cell
What cells are at most risk od damage by radiation?
cells that are actively dividing
What is the half life?
the half life of a radioisotope is the length of time it takes for one half of the mass of the substance to undergo radioactive decay
