Which of these is an example of a chemical change?

feeling ice melt on your skin

crushing ice with a hammer

smelling sprayed perfume

leaving she's out to get moldy

Explain what a limiting reactant is and why it is important in stoichiomerty?

How many valence electrons do most of the noble gases have

You come across a thick deposit of shale that forms a layer in the ground. What can u infer about the area's past environment

How does paint from car keep it from rusting?

Describe 2 theories for yawning

Andy has two samples of liquids. Sample A has pH of 4, and sample B has a pH of 6. what can Andy conclude about these two samples? Sample A is a neutral b alkali c acidic Sample B is a neutral b alkali c acidic

How does a lone pair contribute to molecular shape? A. It is too small to affect the molecule's shape. B. It takes up space like an "invisible" atom. C. It forces the molecule into a tetrahedral shape. D. It lets the bonding pairs spread out more.

The are of a rectangle is 12 in^2. what is the area in cm^2. there are 2.54cm in an inch.

Which statements describe advantages of models? Check all that apply. Models make it possible to easily notice patterns. Models can be used to communicate and test design ideas. Models allow scientists to predict relationships.

Are energy levels and orbitals the same thing?