Which of the following has a positive charge?
Protons are subatomic particles with a positive charge.
What is the smallest possible particle of an element that still retains its properties?
An atom is the smallest unit of an element that retains the properties of that element.
What is a molecule?
A molecule consists of two or more atoms chemically bonded together.
What is formed when two or more atoms of the same element combine?
When two or more atoms of the same element combine, they form a molecule of that element.
Which of the following is an example of a molecule made from different elements?
H₂O, or water, is a molecule made from different elements: hydrogen and oxygen.
Who was the first person to draw an atom including electrons surrounding the nucleus?
Rutherford was the first to propose a model of the atom with electrons surrounding the nucleus.
Which of the following is the simplest element?
Hydrogen is the simplest element, consisting of one proton and one electron.
The chemical symbol for manganese is
The chemical symbol for manganese is Mn.
Which of the following is the correct symbol for Sodium?
The correct symbol for Sodium is Na.
How many elements are approximately found in nature?
Approximately 120 elements are found in nature.
What are the sub-atomic particles present in an atom?
An atom consists of electrons, protons, and neutrons.
Which of the following elements is found in a gaseous state?
Oxygen is found in a gaseous state at room temperature.
What is the correct symbol for Calcium?
The correct symbol for Calcium is Ca.
What do atoms combine to form?
Atoms combine to form molecules.
Which of the following is not a correct symbol-element match?
The symbol for Phosphorous is P, not S.
Which of the following elements is correctly paired with its symbol?
Aluminium is correctly paired with its symbol Al.
Which of the following is a property of metals?
Metals are malleable and ductile, meaning they can be drawn into wires and sheets.
Which of these is not a characteristic of non-metals?
Non-metals are generally poor conductors of electricity.
What is one major difference between metals and non-metals?
Metals are typically shiny and malleable, whereas non-metals are often dull and brittle.
What is a compound made of?
A compound is made of two or more elements that are chemically combined.
Which of the following is a compound?
Water is a compound made of hydrogen and oxygen.
Which of the following is a correct example of a mixture?
Air is a mixture of various gases like nitrogen, oxygen, and carbon dioxide.
What is the chemical formula of common salt?
The chemical formula of common salt is NaCl.
How can the components of a mixture be separated?
The components of a mixture can be separated by physical methods such as filtration, distillation, or chromatography.
Which of the following is a compound used in cleaning?
Washing soda is a compound used in cleaning.
Which gas makes up the largest portion of air?
Nitrogen makes up the largest portion of air, approximately 78%.
How do compounds differ from their elements?
Compounds have different properties compared to the elements they are made from.
What type of mixture is steel?
Steel is a mixture primarily composed of iron and carbon.
Which of the following is not a source of carbon dioxide?
Photosynthesis absorbs carbon dioxide rather than releasing it.
Which human activity releases carbon dioxide into the atmosphere?
Burning fossil fuels releases carbon dioxide into the atmosphere.
What is one harmful effect of carbon dioxide on human health?
High levels of carbon dioxide can affect the lungs and respiratory system.
Which method is used to separate insoluble solids from liquids?
Filtration is used to separate insoluble solids from liquids.
What is the liquid called that passes through the filter paper during filtration?
The liquid that passes through the filter paper during filtration is called the filtrate.
Which method involves cooling a hot saturated solution to get solid crystals?
Crystallization involves cooling a hot saturated solution to obtain solid crystals.
Which technique is best for obtaining pure drinking water from sea water?
Distillation is best for obtaining pure drinking water from sea water.
What happens to solid substances like iodine during sublimation?
During sublimation, solid substances like iodine turn directly into vapour without melting.
Which separation method uses paper and a solvent to separate dyes?
Chromatography uses paper and a solvent to separate dyes.
Which one of the following materials sublimes when heated?
Camphor sublimes when heated, turning directly from a solid to a gas.
In distillation, what is the term for the purified liquid that is collected after condensation?
In distillation, the purified liquid collected after condensation is called distilled water.
What is left behind in the flask after distillation of sea water?
After distillation of sea water, salt and impurities are left behind in the flask.
Which separation method is ideal for separating components of ink?
Paper chromatography is ideal for separating the components of ink.
Why does crystallization work to separate salt from water?
Crystallization works to separate salt from water because salt forms crystals after the water evaporates.
Which apparatus is used to cool down vapours in distillation?
A condenser is used to cool down vapours in distillation.
In sublimation, the vapour directly turns into:
In sublimation, the vapour directly turns into a solid.
Which one of these methods is used to purify solids like iodine?
Sublimation is used to purify solids like iodine.
During paper chromatography, the solvent moves up the paper carrying:
During paper chromatography, the solvent moves up the paper carrying dyes or colors.