A liquid is heated and a solid forms at the bottom of the beaker. Is this a physical or chemical change?

The balanced equation for a hypothetical reaction is a 5b 6c → 3d 3e. what is the rate law for this reaction?

How many atoms of gallium are in 2.85x103 g of gallium?

Identify the catalyst in this reaction, explain how you know it is the catalyst, and describe how it increases the rate of the reaction.

Which information in the periodic table indicates the number of protons in an atom? A. the position of the element in its column B. the element's chemical symbol C. the element's atomic mass D. the element's atomic number

The formula of copper sulfide is CuS but the formula of copper sulfate is CuSO4. State and explain the names of the compounds with the formulae Na3P and Na3PO4. Na3P: Na3PO4: explanation:

What is the pressure, in mm Hg, of 2.50 moles of an ideal gas if it has a volume of 50.0 liters when the temperature is 27.0° C?

What element has the same valence electrons as carbon A) N B) AI C) Si or D) Be

What element is represented by the following electron configuration: 1s22s22p63s23p64s23d4 Question 2 options: Cr Ca Ge Ar

He substance, cocl2, is useful as a humidity indicator because it changes from pale blue to pink as it gains water from moist air. What is its name?

The weighted average atomic mass of an element depends upon the a. relative abundance of protons in the element b. mass and relative abundance of each isotope of that element c. mass and relative abundance of each neutron of that element d.