Unit 1

Science watches and measures the Universe

What is the Universe?

The Universe is everything existing

Everything existing in the Universe only can be

matter or energy

What is matter?

● Matter is everything that takes up space and has mass

What is energy?

Energy is everything that can work

What is Sciencie?

● Science is the knowledge based on observation, experimentation and logic reasoning.

● The scientific method is the way Science works: watching, measuring, predicting, checking...

What is ”to measure”?

● The properties of matter that can be measured are called magnitudes

● Ejemplos: length, volume, surface area,...

● Base Magnitudes define themselves. Example: length.

● Derived Magnitudes are defined from a combination of the base magnitudes. Example: speed.

To measure is to compare a propertie of an object with a standard

● The unit of measurement is a reference or standard.

● Example: the metre.

● The measure instrument counts how many times are the standards in the object.

● Example: tape measure.

The International System of Measurements

Multiples and submultiples

Derived units

The derived units are obtained from a combination of the base units. They are used to measure surface area, volume, speed, density, etc. These units are the square metre, cubic metre, metre per second, etc.

Properties of matter :Mass

● The mass is the amount of matter in a body.

Weight

● Weight is the force generated by the gravitational attraction of the Earth on a body.

Volume

● Volume is the amount of space occupied by an object.

Surface Area

● The surface area is the space occupied by the length and width of a body.

Density

● The density is the relationship between the mass and the volume of a body, that is, how concentrated the mass is in a specific volume.

d = m/v

What is matter made off?

● All matter is made up of atoms.

● An atom is the smallest particle of matter which can exist alone.

The structure of an atom

● Proton● Electron● Neutron● Quarks

How are atoms organised?

● Molécules: are made up of two or more atoms.

● Crystals: consist of atoms or molecules arranged in a regular, organised structure.

Elements in the Universe● All atoms in the Universe

are made up of the same particles, the only difference is the number of particles.

● The number of protons in the nucleos of an atom is the atomic number.

● Chemical Element is a substance that contains one type of atom, so all atoms have the same atomic number.

How are elements classified?

Elements and compound substances

● Chemical Element is a substance that contains one type of atom. It cannot be broken down into anything simpler by chemical reaction..

● The combination of elements produce millions of compound substances.

● Each element has its own chemical symbol. To describe molecules a chemical formula is used.