Science Review :

Science Review:

Mid-year Exam

Format of the exam

• Part A– 25 Multiple choice answers (2 pts each)

• Part B– 10 One-word answers (1 pt each)

• Part C– 8 Short answers (40 points)

Topics : Group 1

• Technical drawing– Lines – Scale – Section – Multiview – Isometric – Tolerance – Dimensioning

Basic Lines

• Visible Contour Line

• Hidden Contour Line

• Center Line

• Extension Line

• Dimension Line

What is the difference?

What is the difference?

Scale

• The scale:– A relationship between an object’s dimensions in

a drawing and the object’s actual dimension

– Drawing size : Real Life size• 1:1 = actual size representation• 2:1 ; 3:1; 25:1 = scale of enlargement• 1:2 ; 1:4; 1:25 = scale of reduction

Purpose of scales• Reduction Scale

– 1:2– 1 mm in the drawing represents 2 mm in real life

• Enlargement Scale– 2:1– 2 mm in the drawing represents 1 mm in real life

• Actual size representation– 1:1– Object is life size

Cross-sections vs Section

• Cross-Sections:– Shows the interior details of an object as if it were

cut by a cutting plane

• Sections:– Shows the interior details of a part of an object as

if it were but by a cutting plane

Cross-Section

Sections

• Revolved Section• Removed Section

Projections

• Orthogonal– Isometric

• All three sides are shown

Projections

• Orthogonal– Multiview

• Shows all three sides with details

Important Definitions

• Dimensioning:– writing the dimensions of an object using extension line and

dimension lines• Multiview:

– type of orthogonal projection that shows all sides with the most details

• Tolerance: – term which describes the required manufacturing precision of

an object.• Actual-size scale: 5:5 or 1:1 …• Enlargement scale: 5:1 or 3:1 …• Reduction scale: 1:5 or 1: 3 ….

The Material World

In less than 30 minutes

Topics: Group 2

• Materials – Types of materials – Justifying materials – States of matter and particle model – Pure substances – Chemical change vs. Physical change – Identification of solid, liquid, gas

Definitions

• Types of material:– Wood:

– Modified wood: material made with wood mixed with other substances (like glue)

– Metals :

– Alloys: combination of metals

Properties

• Malleable• Ductile• Hardness• Elasticity• Resilience• Stiffness

Matter and the particle model

• Everything around us is made of atoms and molecules

• To simplify how we see things, we will represent these tiny atoms and molecules using the particle model

• An element is more of the same particle

• A compound is when there are two or more types of elements/ atoms in a molecule (the particles must be touching)

Elements turn into compound through chemical reactions that result in a gain of mass or a change of color

Moral of the story

• A pure substance is when a substance has the exact same chemical composition

• A mixture is well, a mixture

Moral of the story

• A pure substance is when a substance has the exact same chemical composition

• A mixture is well a combination of more than 1 type of molecule or element

• Would salt water be considered a pure substance?

• What are the 2 signs for changing an element into a compound?

• Is O2 an element or a compound?

Physical Change vs. Chemical Change

• Physical Change– The chemical nature of the substance stays the

same• Dillution• Dissolution• Phase Change

• Chemical Change– The chemical nature of the substance is altered

Properties

Density

• Density (ρ) is mass on Volume– ρ = m/V

• ρ is different from p

• m = How much matter it has• V = how much space does it take up

The General rules…

Regular solids

Irregular solids

Liquids Unit

mass Weigh Weigh Liquid mass g

Volume Length x width x height

Water Displacement

Measure it in the graduated cylinder

ml or cm3

Density m Weigh Liquid mass g/ml or g/cm3

v Water Displ. Measure in g.c.

Identifying solids

• Best to verify density• Color• Electrical conductivity• Boiling point• Melting point• Magnetism

Identifying liquids

• Cobalt Chloride – positive test = water

• Electrical conductivity– positive test = either salt water, acid or base

• Blue litmus paper– if it turns red = acid

• Red litmus paper– if it turns blue = base

Identifying Gases

• Flaming Splint– Positive test = hydrogen

• Glowing splint– Positive test = Oxygen

• Limewater– Positive test = Carbon Dioxide

Science Review

Topic 3: The Circulatory System

Topic: Group 3

• Heart anatomy • Blood function • Blood typing

• Immunity

Anatomy

• The circulatory system is the UPS system of your body it delivers nutrients, O2 and waste where it is needed

– O2 + glucose → water + CO2 + ENERGY

• Blood Vessels• Heart

Anatomy

• The Blood Vessels– Arteries

• Arterioles

– Veins• Venules

– Capillaries

Arteries - going away from the heart

Veins - going towards the heart

Capillaries – where the exchanges occur

Anatomy

• Important Arteries around the heart

– Aorta • All oxygenated blood (arterial blood) leaves the heart

from this artery

– Pulmonary arteries• The de-oxygenated blood leaves the heart towards the

lungs

The pulmonary arteries are the exception – it does not contain arterial blood

Anatomy

• Important Veins around the heart

– Vena Cava (inferior and superior)• Blood from the body enters the heart by these two

veins

– Pulmonary veins• Oxygenated blood (arterial blood) from the lungs enter

the heartThe pulmonary veins are the exception – it does not contain venous blood

Anatomy

• The Heart– Stimulates the movement of the blood– Hollow muscle with 4 cavities/chambers

• Right Atrium• Right Ventricle• Left Atrium• Left Ventricle

RA LA

RV LV

Anatomy

• Blood always circulates from an atrium to a ventricle.

ATRIUM

VENTRICLE

Atrioventricular valve

Anatomy

• The Heart– The contractions of the heart causes blood to

circulate

Anatomy

• The heart – Pulmonary Circulation

• Brings blood to and from the lungs

– Systemic Circulation• Brings blood to and from the cells

Circulations

• Left side of the heart– Oxygen from the lungs travels through the

pulmonary veins to the left atrium– The heart then contracts and pumps the blood

from the left atrium to the left ventricle– The heart pumps again and pushes the oxygen rich

blood from the ventricle to the aorta– The blood then travels through various arteries to

get to the capillaries and the cells, where diffusion occurs

• LA – LV – aorta - cell

Circulations– Right side of the heart– The blood, now rich in CO2, travels through the capillaries

and various veins until it reaches the superior vena cava or the inferior vena cava

– From the vena cava, the CO2 rich blood enters the right Atrium.

– The heart contracts and pumps the blood from the right atrium to the right ventricle

– The heart pumps again and pushes the CO2 rich blood from the ventricle to the pulmonary arteries where it will return to the lungs to exchange the CO2 for O2

Circulations

• The proper way to divide the circulations of the body is the following:– Systemic Circulation

• From the heart (LV) to the cell and then back to the heart (RA)

– Pulmonary Circulation• From the heart (RV) to the lungs and then back to the

heart (LA)

Blood

• Components

1. Plasma 55%2. Red blood cells (RBC) 45%3. White blood cells (WBC) (less than 1%)4. Platelets (less

than 1%)Plasma – Liquid part of the blood

Red blood cells – carries oxygen and carbon dioxide

White blood cells - protect your system

Platelets – allow blood to coagulate

Blood types

• Certain substances (agglutinogens) are found on the membrane of the red blood cell

– Substance A– Substance B– Rh factor

– The presence of these substances determines your blood type

Transfusions

• The injection of blood into a person

• Donor and Recipient

• Rule of transfusions:– The donor’s blood must not carry substances that

differ from those on the red blood cells of the recipient. Their blood must be compatible.

Blood CompatibilityDonors

AB+

AB-

A+ A- B+ B- O+

O-

RECIPIENTS

AB+

AB-

A+

A-

B+

B-

O+

O-

Compatibility

• Transfusions are possible when both donor and recipient have the same blood type

• People with type O- can donate to anybody and are called universal donors

• People with type AB+ can receive from anybody and are called universal recipients

Immunity

• White blood cells

• Important definitions: DEFINITIONS

Injection of weak or dead antigensResistance to a disease following injection of

weak or dead antigensSubstances made by the white blood cells

VaccineImmunityantibody

Beginning of flu End of flu

Virus

Temperature

Antibodies