Answer: Potassium-40 decays into argon gas over time.
Explanation: Potassium-argon dating is a dating method used to determine the age of sedimentary rocks by comparing the proportion of K-40 to Ar-40 in a sample of rock, and knowing the decay rate of K-40.
Potassium-40 undergoes decay following first order kinetics as given below:
Answer: summation
Explanation:
The process which determine if an action potential will be generated or not depends on the combined effects of the signal inputs from multiple sources of synapse or from the repeated signals from the same synapse.
If the input signals reach the threshold voltage, action potential will be generated. (all –or –none principle).Therefore, this process is a determinant of the likelihood of action potential generation and it is called summation.
Summation is the ability to integrate multiple PSPs at multiple synapses.it is the process that determine if an action potential will be generated by combined effects of inhibitory or excitatory signals.
Based on the pathways and voulme of applied stimuli in the presynaptic neuron;
The signals can be temporal summation ( consecutive signals produced from the same synapse)where action potential of high frequency in the PSN generated action potential in the post synaptic neuron, which summate with one another. Or Spatial where signals inputs are from multiple presynaptic cells.
