I think c is the answer but I could be wrong..
Isotopes are variants atoms of the same element, having same number of atomic(proton) number but different number of neutrons and mass number.
Considering iron-60
- The atomic number which also equals the number of protons for the element iron as can be seen on the periodic table is 26
- The name iron-60 also tells us that this particlar isotope's mass number is 60.
- The chemical symbol for Iron is Fe
Now expressing as an isotope iron-60 becomes ⁶⁰₂₆Fe ( very unstable )
Other stable isotopes of Iron include ⁵⁴₂₆Fe , ⁵⁶₂₆Fe, ⁵⁷₂₆Fe and ⁵⁸₂₆Fe
See more here: brainly.com/question/11236150
The last one, answer is D
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.
I believe the answer I’d D
Hope it helps