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WorksheetsLesson 2 - Chemical Basis of Life (Intro to RT & HC)
Total questions: 51
Worksheet time: 41mins
The study of Chemistry begins with the basic unit of matter called ____.
Atom
Molecules
Atomic Particles
Moles
Democritus first used word "atomos" , meaning "indivisible".
False
True
Atoms are composed of 3 main particles (subatomic particles)
- protons (+)
-neutrons
-electrons (-)
True
False
Atoms have equal numbers of electrons and protons because these subatomic particles have equal but opposite charges, atoms are neutral.
True
False
Counts the number of protons in an atom.
(a)
All atoms of an element have the same number of protons.
True
False
Are the building blocks of all matter.
(a)
Any substance composed of two or more elements.
(a)
Elements cannot be decomposed into simpler matter.
True
False
• Do not contain C-H- bonds
• Mineral in nature
Element
Compound
Inorganic Compounds
Organic Compounds
• Have higher melting and boiling point
• More soluble in water and other polar solvent
Compound
Elements
Organic Compound
Inorganic Compound
• Contain C-H bonds
• Biological in Nature
Organic Compounds
Inorganic Compounds
Compound
Element
• Have low melting point and boiling point
•Less soluble in water and other polar solvents
Atoms
Inorganic Compounds
Organic Compounds
Molecules
• Smaller and less complex in nature
• In solution, they break down into ions and conduct electricity
Inorganic Compounds
Organic Compounds
Molecules
Atoms
• Larger and complex in structure
• Do not conduct electricity unless they are salts formed with inorganic acids and bases
Atoms
Organic Compounds
Inorganic Compounds
Molecules
Four main types of organic macromolecules:
Carbohydrates
Water
Lipids
Proteins
Nucleic Acids
• It is the most abundant compound on earth
• Only substance existing naturally in all states of matter
(a)
Water is tasteless, odourless, transparent, incompressible liquid and it is 60-90% of total chemical component of the cell.
True
False
Maybe
Properties of Water :
Polarity
Cohesion and adhesion
Acid
Capillary action
Heat capacity
The electrons in an atom are located at different energy levels.
True
False
Electrons in the highest energy level are called
(a)
By moving electrons, the two atoms become linked. This is known as
(a)
This stability can be achieved one of two ways :
Ionic bond
Chemical bond
Covalent bond
Involves transfer of electrons between two atoms.
(a)
An atom or group of atoms which have lost or gained one or more electrons, making them negatively or positively charged.
(a)
What are positively charged ions (+) called?
(a)
What are negatively charged ions (-) called?
(a)
Are made of oppositely charged ions.
(a)
Are atoms held together by attraction between a (+) and a (-) ion.
(a)
Compound is neutral overall, but still charged on the inside.
True
False
An (a) is any ionic compound that releases hydrogen (H+) in solution.
A (a) is any ionic compound that releases hydroxide (-OH) in solution.
Measured by concentration of hydrogen ions (H+)
Acidity of a solution
pH ranges
Acid
Ions
(a) acids have a sour taste.
(a) acids are highly corrosive.
C6H8O6 , Vitamin C
(a)
C6H8O7, a weak organic acid in citrus fruits.
(a)
H3PO4
(a)
Strong acids completely dissociate in water.
True
False
Not sure
Maybe
Weak acids DO NOT completely dissociate in water.
True
False
Not sure
Maybe
It makes up most of living organisms, contains bonds between two or more CARBON atoms. Can easily bond with up to 4 other elements.
(a)
It is versatile, can be "backbone" of long chains or rings.
(a)
Organic molecules can be extremely large and complex; these are called
(a)
Bases are also called (a) substances.
Compounds that dissociate in water and produce cations other than H+ and anions other than OH- are called
(a)
The most familiar salt is (a) , the principal component of common table salt.
NaHCO3 (Salt)
(a)
MgSO4 (salt)
(a)
Certain salts, called (a) , can combine with excess hydrogen (H+) or hydroxide (OH-) ions.
Antacids are buffers made of the salt calcium carbonate (CaCo3)
True
False
Not sure
Maybe
• Act like a chemical sponge to soak up excess acid or base, keep pH constant.
• Are vital to maintaining pH in organisms.
(a)
