7. Suppose each of these isotopes emits a beta particle. Give the iso- tope name and symbol for the isotope that is produced. Place a
checkmark next to the symbol for isotopes that are stable. (Consult
the isotope graph on page 66 of Lesson 14: Isotopia.)
a. potassium-42
b. iodine-131
C. iron-52
d. sodium-24

All the elements are arranged by melting points on the periodic table. in row they go from metals to gasses. in the row from sodium to argon, sodium is more reactive than the one on its right, magnesium.

Hi + naoh -> h2o + nal

The population of unionid mussels decreased after zebra mussels were introduced. zebra mussels competed with the unionid mussels for food. the zebra mussels were able to displace the unionid mussels, allowing the zebra mussel population to increase  over the years. the unionid mussel population decreased because  of lack of food.