Butter melts when you heat it in a pan or on the stove is this a chemical change or a physical change? how can you tell?

According to the law of conservation of mass, if an element A has an atomic mass of 2 mass units and element B has an atomic mass of 3 mass units, what mass would be expected for compound AB? for compound A2B3?

A compound has a molar mass of 86.0 g/mol and an empirical formula of C3H7 what is the molecular formula

Consider the reaction of hydrogen gas with chlorine gas: H2 + Cl2 → 2HCl 4 molecules of hydrogen gas react with 6 molecules of chlorine gas. 4 molecules of hydrogen gas in this reaction will produce 8 molecules of HCl.

Before allowing an employee to enter an excavation at least four feet deep in must be tested for oxygen deficiency and toxic fumes. True or false

Potential energy can be defined as:

A group of students wants to see how temperature affects the time it takes for spilled water to dry up in the investigation what will be the dependent and independent variables

What is not true of white light?

Diatoms and some yeasts are unicellular eukaryotes that have mechanisms of nuclear division?

Consider the circuit 9.012 9.012 What is its equivalent resistance? Answer in units of 12.

out of 2.00 50 mL of water is added to 30 mL of a 0.50 M salt solution. What is the new concentration? (To write your answer using scientific notation use 1.0E-1 instead of 1.0 x 10-1)