Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.
The fourteen elements (atomic number 90-103) after actinium are called?
Actinoids
Nucleotides
Pre-actinum elements
Atomic elements
Correct answer is A
The actinide or actinoid series encompasses the 15 metallic chemical elements with atomic numbers from 89 to 103, actinium through lawrencium.
The actinide series derives its name from the first element in the series, actinium.
Electron gain enthalpy
Ionization enthalpy
Enthalpy change
Enthalpic gas removal
Correct answer is B
- The enthalpy change associated with the removal of the first electron from an isolated gaseous atom.
- Ionization enthalpy is the minimum amount of energy required to detach from an isolated gaseous atom the most loosely bound electron and turn it into a gaseous cation.
In troposphere, the two types of pollutants are?
Gaseous and particulate pollutants
Carbon and metallic pollutants
Natural and man-made pollutants
Sulphuric and nitrogenous pollutants
Correct answer is A
- The troposphere is the first and lowest layer of the atmosphere of the Earth.
- Gases mix at this layer.
- Weather occurs here
- Region where plants and animals breathe and live
- Tropospheric pollution is caused due to the presence of unwanted gaseous or solid components in the air.
One of the following is not a physical property of monosaccharides?
Monosaccharides get charred when heated
Monosaccharides are water-soluble, sweet substances
They are highly vital to the exploration of metals
They can be reduced to sugar alcohols
Correct answer is C
- Monosaccharides are reducing sugars.
- Pure monosaccharides are water-soluble, white, crystaline solids.
- They taste sweet
- Form a black residue of carbon when dehydrated
The compounds made up of only carbon and hydrogen are called?
Carbon compounds
Hydrocarbons
Atoms
Carbon hydrolysis
Correct answer is B
A hydrocarbon is any of a class of organic chemicals made up of only the elements carbon (C) and hydrogen (H).
Classes are Aliphatic and Aromatic Hydrocarbons.
Natural sources are coal, natural gas and petroleum.