What will be formed when a protostar attains its gravitational equilibrium?

• Main sequence star

• Red Giant

• Supernova

• White dwarf

Who created a classification of elements based on their atomic weight?

• Carlo Perrier

• Dmitri Mendeleev 

• Emilio Serge    

• Henry Mosely

When the elements were arranged according to their atomic numbers, there were four gaps in the table. What are the atomic numbers of the four missing elements?

• 23, 45, 67, 98  

• 43, 61, 85, 87

• 2, 6, 18, 45

• 42, 68, 85, 87

What is the general formula for most carbohydrates?

• Cn(H2O)n

• CnH2nOn

• CH3(CH2)nCOOH

• CnH2n+2

Which of the following would NOT increase the rate of reaction?

• Adding catalyst

• Increasing the concentrations

• Increasing the temperature

• Increasing the volume

What is the electronegativity difference between Si (1.8) and F(4.0)?

• 0.8

•  1

• 2.0

• 2.2

At what stage does the outer covering of a star blow due to insufficient energy?

• Protostar

• Red giant

• Supernova

• White dwarf

What is the molecular shape of BeF3?

• Linear 

• Trigonal

• Tetrahedral

• Trigonal bipyramidal

Which of the following pairs of atoms are bound by a polar covalent bond?

• Cl-Cl

• Mg-O

• N-H    

• C-S

Which of the following is considered as the building block of proteins?

• amino acids

• nucleic acids

• nucleotides

• polypeptides