Ex.2. p.111 Read the texts, watch and listen and then fill in: universe,DNA,helix, elements, properties. ⦁ The periodic table of the elements – Dmitri Mendeleev- 1869 This Russian chemist organized all the chemical (1)… Into groups based on their (2) … and left spaces for new elements to be discovered. This information is known as the periodic table of the elements and is used all over the world. ⦁ The Big Bang Theory – Georges Lemaitre – 1920s. A Belgian physicist and astronomer was the first to suggest that our (3)… is expanding from a single poiunt. His ideas became known as the Big Bang Theory which is one theory for how the universe was created. ⦁ DNA structure – James Watson &Francis Crick - 1953. American scientist James Watson and British scientist Francis Crick discovered that our (4) … is not flat, out a 3D structure that twists around in a double (5)