In my opinion, the correct answer among the choices listed above is option C. The Big Bang Theory states that between 15 and 20 billion years ago, the universe began expanding out of an enormous explosion. However, the exact number is approximately 13.8 billion years ago.
As in an element?
He/ Helium
<span>The nature of potential energy is that the zero point is arbitrary; it can be set like the origin of a coordinate system. That is not to say that it is insignificant; once the zero of potential energy is set, then every value of potential energy is measured with respect to that zero. Another way of saying it is that it is the change in potential energy which has physical significance.
Hope this Helps! </span>
<span>Animal Y is an invertebrate, and animal Z is a vertebrate.
An x-ray can produce images of structures found inside the body. Based on the image, you can see that Animal Z has a backbone, which is a series of small bones called vertebrae that extend from the head. Animal Y does not have that structure.
Vertebrates are organisms that have a backbone and invertebrates are organisms that lack one. </span>