Sodium (na) and potassium (k) are in the same group in the periodic table. sodium is in the 11th position. how many valence electrons does potassium have?

What type of organism is a one-celled organism that functions as a single unit? a. bi-celled b. single-celled c. pre-celled d. multi-celled

What are two ways that harvesting algae from the ocean may benefit human society? how might the harvest of algae negatively impact the ocean communities where that algae grows? how could this be prevented?

The activity of the modern sample is 1.10 bq . how long does that measurement take?