Witch substance is a combination of different atoms

A - homogeneous mixture

B - heterogenous mixture

C - element

D - compound

A particular first-order reaction has a rate constant of 1.35 * 102 s-1 at 25.0°c. what is the magnitude of k at 75.0°c if ea = 85.6 kj/mol?

If an unknown element didplays many extremly strong metallic properties, where is it most likely to be located on the periodic table? a: far right b:along the stair step c:middle d:far left

How does the amplitude of a wave show how much energy is in the wave?

What will most likely happen if a sound wave moves from the air through a solid? a. it will increase wavelength b. it will decrease in speed c. it will increase in speed d. it will decrease in wavelength

Explain why subscripts cannot change when balancing a chemical equation

An ice cube at 0.00 ˚C with a mass of 8.32 g is placed into 55 g of water, initially at 25 ˚C. If no heat is lost to the surroundings, what is the final temperature of the entire water sample after all the ice is melted (report your answer to three

When metals combine with nonmetals the metallic atoms tend to

Which type of bond forms between water molecules? a. strong bond b. hydrogen bond c. covalent bond d. polar bond

Down syndrome is caused by the presence of an extra copy of chromosome 21. how would a karyotype identify a person with down syndrome? a) ID physical characteristics of someone with the disease.

Which expression is a measurement of denisty