Answer:
They found evidence of an impact crater in Mexico
Explanation:
The K-Pg boundary is the boundary between the Cretaceous period and the Paleogene period, but also marking the end of the Mesozoic era and the beginning of the Cenozoic era. This boundary is dated to roughly 66 million years ago. The K-Pg boundary is characterized with a mass extinction. The dominant organisms on Earth all died out, including the dinosaurs, both terrestrial and aquatic, as well as the flying reptilians, with only the birds surviving from that super-family. The reason for the mass extinction has been an impact with an asteroid or a comet, that was very large and hit the Earth where the Yucatan Peninsula in modern day Mexico is located. The impact was devastating, with heat waves, tsunamis, earthquakes, triggering of the majority of the volcanoes, wildfires, all combined managed to devastate the environment, thus big portion of the species living in it as well. The lucky survivors were smaller organisms, and the mammals turned out to be the most successful in occupying the empty niches and have became the dominant organisms on the planet.
Answer:
The atom, the basic building block of matter, consists of a core nucleus surrounded by negatively charged electrons. Inside the atom nucleus contains a mixture of positively charged protons, and electrically neutral neutrons. All atomic electrons bind to the nucleus through electromagnetic force. A ground of electrons bound together will form individual molecules. An atom with an equal number of protons and electrons will hold neutral. An ion has positive or negative charge, either through a lack of electrons or an electron excess. The number of protons determines the formation of chemical elements, while as the number of neutrons determines the element's isotope. Most of the atom's mass has a concentration compacted within its nucleus; however, protons and neutrons hold about the same mass. Electrons bound to atoms hold a percentage of stable energy levels, otherwise known as orbitals, which undergo transitory processes through absorbing or omitting photons with equal energy levels. Electrons determine an element's chemical properties, thus influencing an atom's magnetic properties.
Explanation:
I'm thinking the brain. The brain produces hormones and chemicals that tell the body to grow. And you also need to think a lot when trying to survive, which is when the brain comes in handy.
Adenosine triphosphate (ATP) production