Has a lot of activities for you to practice on that have no answers
Has summary notes that provide clear explanations on key concepts of Agricultural science grade 11
Topic 1: Basic chemistry
What is chemistry?
Chemistry is the study of the properties, composition and structure of matter, the
changes that occur in matter, and the energy that is released during these changes.
1. Important chemistry terminology
Matter- Is anything that can occupy space and has mass (it weighs
something) and volume (it take up space)
Atom- is the smallest unit of matter that cannot be broken down by
chemical means
They are made up of the following sub-atomic particle; neutron,
proton and electron
Proton- is a subatomic particle with a positive charge
Neutron- is a subatomic particle with no charge
Electron-is a subatomic particle with a negative charge
Valence electron- is the electron in the outer shell of an atom
It is determined by the main group number of an element found in
its column in a periodic table e.g Carbon is in group 4 and has 4
valence electron
Atomic number- number of protons in the nucleus of an atom
Atomic mass number- number of protons and neutrons in the
nucleus of an atom
Element- is a substance that cannot be broken down into simpler
substance by chemical means (element adhere to form a molecule)
Molecule- is a group of two or more atoms which are bond
together to form a compound (molecule can be broken down
chemically into elements they made up of)
e.g water molecule (H2O) is made up of two hydrogen atom and
one oxygen atom
carbon dioxide (CO2) is made up of 1 carbon atom and two
oxygen atom
Compound- substance that result from a combination of two or
more different elements
Periodic table- is the table of all the known elements arranged in
order of their atomic number
Isotopes- element that has equal number of proton but different
number of neutrons
1 By Mr E.C. Mabuza
,Agricultural sciences -Notes- Grade 11
Mixture- two or more substance which has been combined such
that each substance retains its own chemical identity.
e.g salt in water (salt dissolve in hot water)
Activity 1 (chemistry concepts)
1.1 Define the following concepts;
(a) matter
(b) Atom
(c) Proton
(d) Neutron
(e) Periodic table
(f) Atomic number
(g) Atomic mass number
(h) Isotope
(i) Element
(j) Molecule
Activity 2 (chemistry concepts)
1.1 analyse the flow chart below and answer the questions based on it
1.1.1 Identify the substance labelled A, B and C (3)
1.1.2 Explain the differences between an element and substance in (2)
1.1.3 Distinguish between the mixtures B and C (2)
2. The periodic table
Is the table of all known chemical elements in order of atomic number.
Elements in a periodic table are arranged in a series of rows and
columns based on shared chemical and physical properties at room
temperature (they may be gas, liquid or solid)
2 By Mr E.C. Mabuza
, Agricultural sciences -Notes- Grade 11
Interpreting a periodic table
Periodic table groups
Groups in a periodic table are numbered 1-18 from left to right
Group 1: made up of alkali metals (note: hydrogen is not
considered a metal)
Alkali metals are very reactive (most reactive group in the periodic
table)
They react violently with water
Has one valence electron
Group 2: made up of alkali earth metals
alkali earth metals are very reactive, but less reactive than alkali
metal
Has two valence electron
Differences between alkali metals and alkali earth metals
Alkali metal: have one electron in their outermost shell
Alkaline earth metal: has two outer shell electrons
Similarities between alkali metals and alkaline earth metals
They are both good electrical and heat conductors
They are the most reactive metals in the periodic table
They have low melting point compared to other metals
3 By Mr E.C. Mabuza
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller BookSquad. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $3.48. You're not tied to anything after your purchase.
