A Reactant R Is Being Consumed in a First-Order Reaction

question 64

Multiple Choice

A reactant R is being consumed in a first-order reaction. What fraction of the initial R is consumed in 4.0 half-lives?

• A)0.94
• B)0.87
• C)0.75
• D)0.13
• E)0.063

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Definitions:

Neurotransmitters

Neurotransmitters are chemical messengers that transmit signals across a chemical synapse from one nerve cell to another, or to a muscle or gland cell.

Synaptic Vesicles

Membrane-bound sacs in the neuron's terminal bulb that store neurotransmitters ready for release at the synapse.

Presynaptic Membrane

The part of the neuron that faces the synaptic cleft and is responsible for the release of neurotransmitters to signal adjacent neurons.

Depolarization

A decrease in the charge difference across a plasma membrane; may result in an action potential in a neuron or muscle cell.