How are eras and periods of the geologic time scale named?

They are named for the places where geologists first described rocks or fossils from that time.
Their names are based on the names of scientists who discovered the rocks and fossils.
They are named after plants and animals that lived during that time.
Their names are based on the number of centuries within that length of time.

Select the correct answer from each drop-down menu.describe what happens to a carbon-11 atom when it undergoes positron emission.the decay of a carbon-11 atom _1_, and this causes it to emit _2_.options for 1: > changes a neutron into a proton> changes a proton into a neutron> is hit with a neutron> reconfigures its protons and neutronsoptions for 2: > a negatively charged electron-sized particle> a positively charged election-sized particle> two atoms and several neutrons> two neutrons and two protons