Chert forms when the tiny shells of marine organisms accumulate on the bottom of the ocean floor. true or false

Both models are effective because they show the valence electrons, and these valence electrons indicate the reactivity of an element.

The answer to the question: choose the correct statement.  a) when ethane reacts with fluorine gas the product is less stable.b) addition reactions of unsaturated hydrocarbons and halogens requires a high activation energy.  c)the double covalent bond within unsaturated hydrocarbons requires a lot of energy to break.  d)the double covalent bond within unsaturated hydrocarbons can be broken easily.is: a) when ethane reacts with fluorine gas the product is less stable.

Ican't see the chart but the density of both nickel and cobalt is 8.90 g/cm3, so it would be one of those.

1small intestine- digestive system2 blood vessels- cardiovascular system3 lungs- respiratory system4 triceps- muscular system5 spine- skeletal systemhoped i can i get brainliest