Iodine-131 is a radioactive isotope. after 7.00 days, 54.7% of a sample of 131i remains. what is the half-life of 131i?

Which type of system must exist for chemical equilibrium 1. Shared system 2. closed system 3. Isolated system 4. Open system

Changes of motion are caused by

Which of the following is a reason for creating hybrid plants? yield more crops increase growing season decrease resistance to herbicides reduce amount of manual labor

The reaction 2NO (g) → N2 (g) + O2 (g) has a ΔH =-180.5 kJ. How much heat will be required to produce 44.8 L of NO by the reverse reaction? 180.5 kJ 301 kJ 322.3 kJ 644 kJ

How is the temperature of a substance is related to kinetic energy of its molecules

Which weighs more 10g of iron or 10g of water

Which pair of elements would combine to form an ionic compound? а b sodium and calcium sodium and chlorine carbon and oxygen carbon and sulfur с d

How many moles are there in 545g of Fe2O3?

How are magic minerals different from Felsic minerals? A. Mafic minerals contains lower levels of iron and magnesium. B. Mafic minerals contain more dark-colored, high-density minerals C.

Which of the following gases in Earth's atmosphere would you expect to find as molecules and which as individual atoms? a. Nitrogen b. Oxygen c. Argon