Match the definition to the correct astronomical term. Prompt 1nonluminous material, whose nature we don't yet understand, but whose presence can be inferred because of its gravitational influence on luminous matter Answer for prompt 1 nonluminous material, whose nature we don't yet understand, but whose presence can be inferred because of its gravitational influence on luminous matter Prompt 2in cosmology, the density that is just sufficient to bring the expansion of the universe to a stop after infinite time Answer for prompt 2 in cosmology, the density that is just sufficient to bring the expansion of the universe to a stop after infinite time Prompt 3the third element in the periodic table; lithium nuclei with three protons and four neutrons were manufactured during the first few minutes of the expansion of the universe Answer for prompt 3 the third element in the periodic table; lithium nuclei with three protons and four neutrons were manufactured during the first few minutes of the expansion of the universe Prompt 4when radiation began to stream freely through the universe without interacting with matter Answer for prompt 4 when radiation began to stream freely through the universe without interacting with matter Prompt 5the energy that is causing the expansion of the universe to accelerate; its existence is inferred from observations of distant supernovae Answer for prompt 5 the energy that is causing the expansion of the universe to accelerate; its existence is inferred from observations of distant supernovae Prompt 6physical theories that attempt to describe the four forces of nature as different manifestations of a single force Answer for prompt 6 physical theories that attempt to describe the four forces of nature as different manifestations of a single force Prompt 7weakly interacting massive particles are one of the candidates for the composition of dark matter Answer for prompt 7 weakly interacting massive particles are one of the candidates for the composition of dark matter Prompt 8the term in the equations of general relativity that represents a repulsive force in the universe Answer for prompt 8 the term in the equations of general relativity that represents a repulsive force in the universe Prompt 9the building of heavier atomic nuclei from lighter ones Answer for prompt 9 the building of heavier atomic nuclei from lighter ones Prompt 10a form of hydrogen in which the nucleus of each atom consists of one proton and one neutron