atoms, elements, compounds, and mixtures

Question 1

what are atoms?

Answer 1

the smallest units of matter that have the properties of a chemical element

Question 2

What kind of property is a charge?

Answer 2

A physical property

Question 3

Charges allow particles to ________

Answer 3

move through or remain still in an electromagnetic field

Question 4

What is an electromagnetic field?

Answer 4

Electromagnetic fields are a combination of invisible electric and magnetic fields of force.

Question 5

What is the charge of an electron?

Answer 5

negative

Question 6

What is the charge of a proton?

Answer 6

positive

Question 7

What is the charge of a neutron?

Answer 7

neutral

Question 8

What particles are in the nucleus?

Answer 8

Protons and neutrons

Question 9

The nucleus has an overall ____ charge. Why?

Answer 9

positive

because neutrons have no charge and protons have a positive charge, so together they make a positive charge

Question 10

Electrons occupy _____ at certain ____.

Answer 10

clouds

energy levels/shells

Question 11

What is an electron cloud?

Answer 11

The general area where an electron may be found. The shell is used for visualization but the cloud is more accurate.

Question 12

When is an atom neutral?

Answer 12

When it has the same number of protons and electrons

Question 13

When is an atom positive?

Answer 13

When it has more protons than electrons (has lost electrons)

Question 14

When is an atom negative?

Answer 14

When it has more electrons than protons (has gained electrons)

Question 15

What is a pure substance?

Answer 15

a substance made up of only one type of atom/molecule (ie an element or compound). Can be either an element or compound (molecule with different elements in distinct ratios)

Question 16

What is a molecule?

Answer 16

Two or more atoms chemically combined. Atoms can be the same or different. All compounds are molecules, not all molecules are compounds.

Question 17

What is a compound?

Answer 17

A molecule with at least two different elements in a fixed ratio

Question 18

What is a chemical substance?

Answer 18

Something that can’t be physically separated into different substances (ie diamonds)

Question 19

Because a compound is reacted chemically, the individual parts no longer ______

Answer 19

have their individual properties

Question 20

Are the parts of a compound always in a fixed ratio?

Answer 20

Yes

Question 21

What is a mixture?

Answer 21

A mix of two or more different substances that aren’t in a fixed ratio (ie salad). The substances are only physically combined and can be separated

Question 22

What are the two types of mixtures

Answer 22

Heterogeneous and homogeneous

Question 23

What is a heterogeneous mixture?

Answer 23

A mixture that doesn’t look the same all throughout. Different parts of it look different and aren’t the same. Can be separated physically

Question 24

What is a homogeneous mixture?

Answer 24

Looks the same throughout. Cannot be separated physically

Question 25

What is filtration?

Answer 25

The act of removing a solid that is not soluble (doesn’t dissolve) from a liquid by pouring the solution with the solid and the liquid through filter paper. Solid collects on paper. a way to separate a mixture

Question 26

What is chromatography?

Answer 26

used to test whether a liquid is a substance or a mixture by putting a dot of something on a layer of silica on a plate and placing it in the solvent (part doing the dissolving(liquid phase), and watching it slowly move up the plate(solid-state). doesn’t test the whole substance

Question 27

What is evaporation as a separation process?

Answer 27

Separates a solvent liquid from a soluble solid by vaporizing the liquid and leaving the solid behind

Question 28

What is a solvent?

Answer 28

The substance that is doing the dissolving in a solution

Question 29

What is a solute?

Answer 29

The substance that is being dissolved in the solvent

Question 30

What is extraction?

Answer 30

removing one compound from another by putting the mixture with a solution where the substance that is wanted is soluble but the other substances aren’t (so only the soluble one is in the solution)

Question 31

What is distillation?

Answer 31

Purifying a liquid by heating a mixture of liquids where the liquids have different boiling points and so when the mixture is put under heat, one evaporates first and is transferred to a different container to be cooled.