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tokens: there are ≈100 M ⊙ of hot gas in the X-ray-emitting bright regions (see Table 3 ). There have been a variety of simulations that predict the amount and isotopic composition of debris from SN explosions. For example, Seitenzahl et al. ( 2013 , hereafter Sei ) list 17 models for a Type Ia explosion of a 1.4 M ⊙ white dwarf, and Woosley Weaver ( 1995 , hereafter WW ) simulate the gravitational collapse of 78 stars with zero-age main-sequence mass ranging from 11 to 40 M ⊙ s and metallicity from zero to solar values. Table 6 lists a few selections of predictions from these references. The WW examples have been chosen because of higher values for the amount of Si ejecta and to show a general trend. Table 6 LMC Abundances and Ejecta Mass The abundances of elements in the LMC ISM have been taken from Schenck et al. ( 2016 ), who give values for material swept up by the brighter LMC SNRs. Table 6 compares our abundance values with these. Although our uncertainties are not small, the elements O, Ne, Mg, and Fe appear to be present in amounts expected from the ISM. The only enhancement measured by the Chandra ACIS is the abundance of Si, which is 1–2× solar. Table 6 lists the Schenck abundances, our ACIS abundances, the mass of each element in 100 solar masses of material with solar abundances, the masses in 100 solar masses of material with LMC ISM abundances, the masses in 100 solar masses of X-ray-emitting material in J0453-6655 as determined by ACIS, and, in the last four rows, masses predicted by four models of SN explosions. In the 100 solar masses of diffuse gas we find ≈0.13 ± 0.05 M ⊙ of Si. Values for other elements are close to those expected for the ISM. Uncertainties are listed in Table 6 only for the element Si, but Table 2 gives all uncertainties in the spectral fits. There is good agreement between ACIS and EPIC results, but there is a dependence on model used, which could be a factor of 2. This is not important for the conclusions to be drawn here. The elements produced in an SN Ia are predominantly Fe (the 56 Ni produced quickly decays to 56 Fe), O, Si, and S. Almost all models yield several tenths of a solar mass of Fe. Our ACIS analysis finds 10× less, including the ISM contribution. Based solely on the lack of Fe, an SN Ia is an unlikely origin. An SN II, from gravitational collapse of a massive star, will have dispersed several solar masses of ejecta, and the amount of material ejected increases with stellar mass. The Si/O ratio generally decreases with increasing pre-SN star mass, but there is considerable variation from model to model. The predominant element ejected in the WW core-collapse simulations is O. All stars with mass above 20 M ⊙ and solar metallicity eject more than 1 M ⊙ of O, well above the ACIS measurement of 0.11 M ⊙ , indicating that the pre-SN star almost certainly is 20 M ⊙ in size. The data also favor an explosion that ejects at least 0.07 M ⊙ of Si and less than 0.1 M ⊙ of O. None of the WW simulations fit