A) 5
Half-life is the time it will take for a quantity to reduce to half its initial value. In this case, uranium will undergo radioactive decay, and after 700 mil years, 5 of the 10 uranium atoms will have decayed.
An air conditioning fan.
An airplane taking off.
A ballerina dancing in toe shoes.
A balloon popping.
The bell dinging on a microwave.
A boom box blaring.
A broom swishing.
A buzzing bee.
Car brakes squealing
A car crashing
A car door closing
A car engine
A car horn
Champagne glasses clicking in a toast
Clog dancing
Computer mouse clicking
A copier machine
A diver splashing into water
Doorbell chiming
A dripping faucet
A foghorn
Firecrackers popping
An open fire crackling
Fireworks exploding
A flag flapping in a strong breeze
Flamenco dancing
A hair dryer
A jack hammer
Jingle bells
Meat sizzling on the grill
Paper crumpling
Paper tearing
Pouring milk into Rice Krispies™ cereal
Radiator pipes clanking
A radio
Railroad crossing signal
The siren on a fire engine
A slinky in motion
Smoothing wood with sandpaper
Someone shuffling cards
A sonic boom
A tap dancer
A tea kettle whistling
Tires squealing when racing
A train moving on the tracks
Vacuum cleaner
Walking in autumn leaves
Water boiling
A waterfall
Waves crashing into a rocky shore
A whistle
Wind chimes
Etc.
The chemical group is the methyl group (-CH3).
Its releasing gas, like the bad things you ate
