Element

Atoms

• Building blocks of matter
• Cannot be seen
• Made up of 3 particles

Subatomic Particles

Untitled Slide

• Proton - Large, positive
• Neutron - Large, no charge
• Electron - tiny, negative

Atomic Number

• Tells you # of protons
• Tells you # of electrons
• whole number
• Found above the chemical symbol

Atomic Mass

• Average mass of an element
• Mass - # = neutron amount
• Usually has a decimal point

Isotopes
Atoms of the same element that have different number of neutrons

Isotopes of the same Element

• Have same # of protons and electrons
• Same Chemical properties
• Different Atomic Masses

Unstable Isotopes

• Occur ratio of protons to neutrons is off
• Too many protons create a repel force
• Force emits particles, creating Radioactivity

Radioactive Isotopes

• Nucleus splits
• Large amounts of energy released
• Can be used to power cities
• Extremely dangerous