Answer: Model B shows how the atoms in the molecule are connected but Model A does not.
John Dalton represented compounds as aggregations of circular atoms and although Johann Josef Loschmidt did not create physical models his diagrams based on circles are two -dimensional analogues of later models . August Wilhelm von Hofmann is credited with the first physical molecular model around 1860 (Fig. 1). Note how the size of the carbon appears smaller than the hydrogen.
Zero-inflated Poisson. One well-known zero-inflated model is Diane Lambert’s zero-inflated Poisson model which concerns a random event containing excess zero-count data in unit time. For example the number of insurance claims within a population for a certain type of risk would be zero-inflated by those people who have not taken out insurance against the risk and thus are unable to claim.
The short rate. Under a short rate model the stochastic state variable is taken to be the instantaneous spot rate. The short rate then is the (continuously compounded annualized) interest rate at which an entity can borrow money for…