Lecture 1 - Elements, Compounds & Mixtures

Question 1

what is matter and its’s 3 states?

Answer 1

matter is anything that has mass, all objects are made of matter.

1. solids
2. liquids
3. gasses

Question 2

what is refractive index?

Answer 2

how light passing through a material is bent

Question 3

what is mailability? - give an example

Answer 3

ability to shape through hammering

-gold jewllery

Question 4

what is ductility? - give an example

Answer 4

ability to be shaped by pulling into a wire

-talantum - dentists instruments

Question 5

what are intensive properties?

give 3 examples

Answer 5

do. not depend on the amount of matter present, can be used to identify substances.
- density, colour, boiling point

Question 6

what are extensive properties?

give 3 examples

Answer 6

depend on the amount of matter present

-mass, volume, weight

Question 7

what are physical properties?

Answer 7

observed by examining a sample of pure substance, they arise from molecular structure and strength of intermolecular interactions

Question 8

what are chemical properties?

Answer 8

observed over the course of a chemical reaction, they arise from the distribution of electrons around the atoms nucleus and the outer electrons

Question 9

what is a pure substance?

Answer 9

fixed set of chemical and physical properties, cannot be separated by a physical process

Question 10

what is a mixture?

Answer 10

a physical blend of two or more pure substances, has variable compositions with different properties for different compositions. mixtures can be separated into components by a physical process

Question 11

what is valency?

Answer 11

ability of an atom of one element to combine with other atoms is controlled by the number of electrons which an atom will give, take or share to form a chemical compound.
Relates to the number of electrons and spaces in the atoms electron shells

Question 12

what is relative atomic mass?

Answer 12

mass of one atom of an element divided by the mass of 1/12 of an atom of carbon-12

Question 13

what is relative molecular mass?

Answer 13

mass of a molecule relative to the mass of carbon-12

Question 14

what is a homogenous mixture?

Answer 14

a mixture in a single phase, the same properties throughout the mixture with uniform appearance

Question 15

what is a heterogenous mixture?

Answer 15

a mixture which has multiple phases, it has variable properties with a non uniform appearance

Question 16

give an example of a heterogenous mix which appears as homogenous

Answer 16

colloids - milk - microscopically heterogenous

Question 17

what is a solution?

Answer 17

a type of homogenous mixture formed when one substance is dissolved in another

Question 18

what are 6 types of separation of mixtures?

Answer 18

filtration, crystallisation, extraction, distillation, magnetism, chromatography