Module 2: Environmental Chemistry Flashcards
How many naturally occurring elements are there in the periodic table
144
The German chemist, who first observed the similarities in the elements on the basis of their properties.
Johann Dobereiner
Who is the English chemist that developed the law of octaves?
John Alexander Newland
A grouping method where three elements have similar chemical and physical properties.
Law of triads
The one who developed the periodic table?
Dmitriv Medeleev
Dmitriv arranged the elements based on what?
Through periods (horizontal rows) and groups (vertical rows) in the increasing order of atomic weights.
A pathway by which two or more substances bond together to form a
new substance.
Chemical Reaction
To write a chemical reaction, the reactant are placed in which side?
Right side
The products are on the which side?
Left side
It does not represent a complete chemical reaction unless it is balanced.
Chemical equation
A balanced chemical reaction has EQUAL number of atoms in both sides of the equation.
True
Refers to some reactions that release energy to their surroundings in the form of
heat.
Exothermic
It is a reaction that need heat energy in order to proceed.
Endothermic
It happens when two or more substances combine to form one
(1) new substance.
Synthesis
It takes place when one element replaces a similar element in the compound.
Single Replacement
