HELP PLS .. The half-life of potassium-44 is 22 minutes. It decays into calcium-44. After 66 minutes, what fraction of the original amount of potassium-44 in a sample
will still be potassium?

In a laboratory, nakisha mixes sodium hydroxide solution with an indicator called phenolphthalein. when combined, they create a pink solution. nakisha wonders if mixing other solutions with phenolphthalein will also create this pink color. how could she use the scientific inquiry process to explore it further?

What are the theoretical properties of a gas at a temperature of 0 kelvin?

Imagine you are standing in the antarctic during the southern hemisphere summer. the sky is clear and blue. there are no clouds in the sky. your shadow is cast on the icy ground. what is the color of the shadow?