2024 Exam SCHS Year 9 Science

Physics (2), Nervous System (4.1), Chemistry (3)

How to calculate speed

Distance/Time

Distance

The amount actually traveled

Displacement

The exact distance an object travelled from start to end point

Velocity Calcuation

Displacement/Time

Newtons first law

An object in motion shall remain in motion unless acted upon by a given force

Newtons second law

Force = mass x acceleration

Newtons third law

Every action has an equal and opposite reaction

Inertia

The tendency of an object to resist a change in motion

Nucleus

Center of Atom

Proton

Positively charged particle

Electron

Negativly charged particle

Neutron

A subatomic particle that has no charge and that is found in the nucleus of an atom

Atomic mass

Number of protons and neutrons

Properties of metals

Lustrous, Malleable, ductile, conductive

Properties of non-metals

Dull, glassy or gaseous in appearance, Low density, brittle, insulator

Valence electrons

Electrons on the outermost shell

Octet rule

States that atoms lose, gain or share electrons in order to acquire a full set of eight valence electrons

Ions

positively and negatively charged atoms

Law of Conservation of Mass

Matter is not created nor destroyed in any chemical or physical change

Why do elements in the same group have similar chemical properties

They have same amount of Valance Electrons which help determine how elements interact with each other

Cation

An ion with a positive charge because of losing an electron

Anion

An ion with a negative charge because it gained an electron

DNA

Deoxyribose Nucleic Acid

What are Complementary Bases

Adenine to Thymine

Cytosine to Guanine

Shape of DNA Molecule

Double Helix

Amino acids

Molecules that combine to form proteins

RNA

Ribonucleic Acid

Transcription

Copying of DNA to RNA (mRNA)

mRNA

Messenger RNA responsible for transcpription and taking the code outside of the nucleus to the ribosome

tRNA

Transfer RNA responsible for translation by gathering necassary amino acids for the process of Translation to make proteins.

Codon

A specific sequence of three adjacent bases on a strand of DNA or RNA that provides genetic code information for a particular amino acid

Translation

Decoding of a mRNA message into a polypeptide chain

Genotype

The genetic information on an allele

Allele

A variation in a gene

Phenotype

An organism's physical appearance, or visible traits (The Genotype Expressed)

Genes

A section of DNA that codes for a protein

Homozygous

Having two identical alleles for a particular gene

Heterozygous

Having two different alleles for a particular gene

Number of chromosomes

46 (23 pairs) - 22 Autosomal and 1 Sex linked pair

Research question

Measurable

Contain what you will be changing and what you will be measuring

Specific

Aim

The purpose for conducting an experiment without making a prediction

Hypothesis

A testable prediction, often implied by a theory

Method

Shows how you collect data and test your hypothesis

Independent variable

The experimental factor that is manipulated; the variable whose effect is being studied.

Dependent variable

The outcome factor; the variable that may change in response to manipulations of the independent variable.

(What you are measuring)

Controlled variables

All those things that must be kept the same during the investigation to produce a valid, fair test.

Validity

The extent to which an experiment tests the relationship between the independent and dependent variables

Repeatability

How well the experimental design ensures that the results can be repeated by the same experimenter

Reproducibility

How well the experimental design ensures that the results can be repeated by a different experimenter

Force

A force is an influence that can change the motion of an object, a push or pull

Normal force

The contact force exerted by a surface on an object

Applied force

A contact force which is applied to an object by a person or another object

Central nervous system

Brain and Spinal Cord

Peripherial Nervous System

Nerves outside the central nervous system