2. Se identifica el objeto de estudio, recopilando información a través de los sentidos y búsqueda
en diferentes fuentes sobre lo que se desea
investigar
a) Observación
b) Experimentación
c) Establecimiento de leyes o teorias​

it's c. (to reduce the greenhouse effect/carbon gasses)

the electromagnetic energy from the sun arrives in the form of visible and invisible light.

the alkaline earth metals (beryllium (be), magnesium (mg), calcium (ca), strontium (sr), barium (ba), and radium (ra)) are a group of chemical elements in the s-block of the periodic table with very similar properties: shiny. silvery-white. hopefully this ? i didn't fully understand the question