Our body needs iron. Certain foods are rich in iron and iron tablets are usually recommended by doctors. but neither the food nor tablets are hard like iron? Why?

What is the composition of magma

The change of matter from a solid state to a gas state

Iron-59 has a half-life of 44 days. a radioactive sample has an activity of 0.64 mbq. what is the activity of the sample after 88 days?

A chemical bond between two atoms results from a simultaneous

The average daytime temperature on the planet Mercury is 683 K. What is this temperature in Celsius? A. 956oC B. 680oC C. 410oC D. 715oC

What happens to the total mass of a substance undergoing a physical change

32 g of sulfur will react with 48 g of oxygen to produce 80 g of sulfur trioxide. if 20 g of sulfur and 100 g of oxygen are placed into a sealed container and allowed to react, what is the mass of sulfur trioxide in the container after the reaction

Water exhibits high levels of cohesion due to the polarity of the molecule (positively and negatively charged sides). given this information, which type of bond is responsible for water's cohesion and which atoms interact to form this bond?

scientist have found many marine fossils on the mountain far from any ocean or sea what is the best explanation for these fossils

The change in energy needed to change the state of a substance is