WorksheetsCHEMICAL ELEMENTS
Total questions: 20
Worksheet time: 10mins
How are the the chemical elements are arranged in periodic table?
Althabetically
In order of increasing atomic number
By melting point
Year of discovery
Who is credited with the invention of the modern periodic table?
Antoine-Laurent de Lavoisier
Dmitri Ivanovich Mendeleev
Alfred Bernhard Nobel
Gregor Johann Mendel
Why does air not have a definite formula?
It depends on the temperature
It sometimes has more water molecules
It is not a compound
Is this an element, a compound or a mixture?
Compound
Element
Mixture
All organic molecules that make up living organisms contain:
Carbon only
Carbon and Nitrogen
Carbon and Hydrogen
Carbon, Hydrogen and Oxygen
What is the right chemical symbol of an ionic compound composed of a cation from a base and an anion from an acid (known as salt)?
NACl3
NaCl
Cl2N
Na4CL
Two elements are in the same container, but are not chemically combined together. Are they a:
Mixture
Compound
Element
Using this image, figure out the correct statement.
A compound is always made up of only two elements
An element is always made up of only one type of atom
An elements is not a substance
Which statement about atoms and elements/molecules/atoms is correct?
Elements always exist as separate atoms
Elements and compounds can exist as molecules
Elements always exist as pairs of atoms called molecules
The noble gases (previously known as 'inert gases' ) do not interact with other substances because their electron shells (valence shells) are completely filled and they have little tendency to gain or lose electrons. Name the most chemically inert element.
Helium (He)
Neon (Ne)
Xenon (Xe)
All of them as they have same number of electrons
Which of these contains two carbon atoms and six hydrogen atoms (molecule of ethane)?
C2H6
Co2H6
H6C2
How many atoms are there in a molecule of sulfur trioxide, SO3?
3
4
5
6
What is the smallest particle?
An element
A molecule
An atom
What is the most common element in the Universe?
Gold (Au)
Oxygen (O)
Hydrogen (H)
Iron (Fe)
State whether sulfur dioxide (SO2) is an element of a compound?
It is an element because it atom's substance have the same number of protons, it is chemically the simplest substance and hence cannot be broken down using chemical reactions.
It is a compound in which sulphur (S) and oxygen(O) are elements joined (atoms share electrons to attain stability).
The metal that is the best conductor of electricity?
Silver (Ag)
Nikel (Ni)
Titanium (Ti)
Look at the melting points of the metals from the periodic table and find out the spoon made from which metal will melt in your hand.
Zirkonium (Zr)
Zink (Zn)
Gallium (Ga)
This element is on matchbox covers and is used to light matches.
Sulfur (S)
Phosphorus (P)
Carbon (C)
Which metal is used in the batteries and can be cut with a knife?
Zink (Zn)
Gold (Au)
Lead (Pb)
Lithium (Li)
Most alkali metals and alkaline earth metals react with water to produce hydrogen. Which metals fizz in water?
Sodium and potassium
Beryllium and francium
