Atoms, Molecules
Is water a molecule?
AND
Give a brief explanation as to why.
Yes.
Because water at its smallest unit is made up of 2 types of atoms bonded together. A molecule is smallest particle of a substance that has all of the physical and chemical properties of that substance. Molecules are made up of one or more atoms.
Give at least a phrase explanation as to why you think this!
Yes, air is a mixture.
It is a mixture of different elements in their gas forms, including oxygen, nitrogen, carbon dioxide, methane
A pure substance is a single type of matter than can be separated into different types of matter by physical means.
True/false?
True
Atoms are made up of three types of particles: protons, electrons, and neutrons.
True or false?
True
How would you describe a homogenous mixture compared to a heterogenous mixture in your own words?
Responses vary
Homogenous mixtures have the same make-up or composition throughout.
Heterogenous mixtures have uneven mixtures of different elements and substances. Different parts of the mixture can be separated through various separation methods, unlike homogenous mixtures.
Is salt water a pure substance?
Why or why not?
No, it's not. It's a mixture.
It contains 2 different types of molecules - the water molecule and the salt (sodium-chloride) molecule.
Molecules are units of 2 or more atoms (elements) bonded together.
True/false
AND
name 2 molecules that make up substances we encounter in daily life.
True
Responses vary. Water, salt, carbon dioxide are all possible examples
Why?
Air is a homogenous mixture because the different elements (gasses) that it contains are evenly spread throughout it. Also, people cannot separate the different parts of air using simple methods.
Why or why not?
Are all pure substances made up just one element? Or pure substances be compounds? Why do you think this?
Yes, oxygen is a pure substance as it is only one element.
All elements, standing alone, are pure substances.
Pure substances can also be made up of one type of compound - and remember a compound is made up of atoms of elements bonded together in specific ways. For example, the water molecule compound is a pure substance. When we see water we are seeing trillions or water molecules all together in a space. The atoms in these molecules can't be separated by physical means. So water (and other stand-alone molecules) are pure substances.