Answer: 2. with two symmetrical shells - mirror images of each other.
the term "crinoid" means: 6. phylum where starfish and sea urchins belong
4. lived inside their shells: 1. exoskeletons are made up of this material
7. multicellular organisms that often live in colonies: 8. individuality of coral is called
Explanation:
Crinoid is a term that can be used to describe the radial symmetry of animals that have oral (side of mouth) and aboral surfaces (opposite to the mouth). It is characterized by the mouth at the top surface and surrounded by the arms for feeding it. This is a characteristic feature of animals like star fish and sea urchins and echinoderm animals.
The exoskeleton is a protective shell which protect the animal from the external environment like water, sunlight and predation.
The multicellular organisms that live in the colonies they form coral reef and individually the are called the coral polyp.
Lithium is an element that has an electronic configuration of 2,1. So when forming bonds, it tries to release one of its electrons in the last shell to reach the octet state. Normally when atoms release electrons they get positive charge since the number of protons which bear positive charge, is higher than number of electrons which bear negative charge. So when reaching its octet state, lithium gains positive charge!
Hope this helps! Tbh am not good at explaining. If u have any doubts, ask me!
Phosphoric acid. Also known as orthophosphoric acid in or phosphoric(V) acid, is a weak acid with the chemical formula H3PO4. The pure compound is a colorless solid.
What are the variables you have? I can't answer if I don't know? Haha. :)