Chemistry
Direction
From the following questions select the appropriate answer.
Q. ‘Dry Ice’ is _____________ .
A) Solid Sulpher dioxide
B) Ice below twenty degree celsius
C) Frozen Carbon dioxide
Description not available. Let’s discuss.
D) Solid Hydrogen peroxide
Discuss
Q. Which of the following is an elemental substance?
A) Neon
Description not available. Let’s discuss.
B) Air
C) Salt
D) Brass
Discuss
Q. Which substance has lower density in solid state than in liquid state?
A) Carbon dioxide
B) Nitrogen
C) Chlorine
D) Water
Description not available. Let’s discuss.
Discuss
Q. Which of the following is neither element and nor compound?.
A) Nickel
B) Air
Description not available. Let’s discuss.
C) Gold
D) Silver
Discuss
Q. Which of the following is not elevated?
A) Benzene
Description not available. Let’s discuss.
B) Iodine
C) Camphor
D) Benzoic Acid
Discuss
Q. Which of the following is a chemical change?
A) Ice melts into water.
B) Melt the wax with heat.
C) Rusting of Iron
Description not available. Let’s discuss.
D) Dissolving sugar in water
Discuss
Q. Which of the following is neither an element nor compound?
A) Air
Description not available. Let’s discuss.
B) Nickel
C) Carbohydrate
D) Gold
Discuss
Q. Which substance is available in three states: solid, liquid and gas?
A) Salt
B) Mercury
C) Water
Description not available, Let’s discuss.
D) Camphor
Discuss
Q. Which of the following is a chemical change?
A) Ice melts into water
B) Melt the wax with heat
C) Dissolving sugar into water
D) Rusting of iron
Description not available. Let’s discuss.
Discuss
Q. The smallest particle of an element that reacts with chemical?
A) Molecules
B) Electron
C) Nuclei
D) Atoms
The basic unit of matter is atom, around 100 picometers, which reacts with chemical.
Discuss
Q. What does the nucleus of an atom consist of ?
A) Electron & Proton
B) Proton & Neutron
Atomic nucleus consists of electrically positive protons and electrically neutral neutrons. These two forces are also called strong force.
C) Neutron & Electron
D) Proton & Positron
Discuss
Q. What are the atoms which have the same number of neutrons but different number of protons?
A) Isotones
The combination of two nuclides is called isotones if they have same neutron number-N, but different proton number-Z. Example: Boron-12, Carbon-13.
B) Isomer
C) Isotope
D) Isobar
Discuss
Q. _________ is easily released from atoms by friction, heat, chemical reactions?
A) Proton
B) Electron
Electrons are easily released and transferred from one atom to another by friction-glass and silk, wax and wool, heat-generating voltage by collision of bumpy metals, chemical reactions-oxidation.
C) Positron
D) Neutron
Discuss
Q. What is the molecular mass of oxygen?
A) 42
B) 16
C) 32
Molecular weight of oxygen is 31.99 and atomic weight is 15.88 and its atomicity is approximately 2.
D) 12
Discuss
Q. What is the atomic number of arsenic (As)?
A) 32
B) 29
C) 33
Arsenic (As) has an atomic number of 33 that indicates, it has 33 protons in its nucleus and 33 electrons around the electron while it is uncharged.
D) 26
Discuss
Q. What are the atoms which have the same number of protons but different number of neutrons?
A) Isotope
The combination of two nuclides is called isotope if they have same proton number-Z, but different neutron (mass) number-N. Example: Carbon-12, Carbon-14.
B) Isomer
C) Isotones
D) Isobar
Discuss
Q. Which side of a dry cell exposes negative electrode?
A) Zinc Bar
B) Carbon bar
A dry cell is an electric battery comprises of zinc anode (cylindrical drum-acts as negative electrode), a piece of carbon cathode (central rod-acts as positive electrode), electrolyte (ammonium chloride in the form of paste) and the vacuum is filled up with manganese dioxide.
C) Copper
D) Sulphate
Discuss
Q. Which is the lightest element?
A) Oxygen
B) uranium
C) Graphite
D) Hydrogen
Hydrogen is the lightest and simplest element on earth ever found. The atomic number and mass number of hydrogen is the same.
Discuss
