A) CNO Cycle B) triple- alpha process C) big bang nucleosynthesis D) r-process
A) when the star has burned all its oxygen B) when the chromium fusion stops C) when the silicon fusion stops D) when the star has used up all its hydrogen fuel
A) Nuclear energy increases until carbon and helium burning occur B) Hydrogen fusion stops, and the pressure in the core decreases. C) Hydrogen fusion continues, and the pressure in the core increases. D) Gravity squeezes the star until helium and hydrogen burning occur.
A) Stellar explosion, or supernova, formed the elements heavier the Fe. B) The big bang nucleosynthesis formed the light elements (H, He, and Li). C) Stellar formation and evolution formed their elements from Be to Fe. D) Stellar evolution formed no elements at all.
A) 75 B) 186 C) 261 D) 111
A) Ni-58 B) Ni-59 C) Cu-58 D) Zn-58
A) John Newlands B) Dmitri Mendeleev C) Julius Lothar Meyer D) Henry Moseley
A) Rn-211 B) At-212 C) At-210 D) Po-211
A) Atomic number is the number of protons, the atoms are arranged by the increasing number of protons B) Atomic number is the number of neutrons, the atoms are arranged by the increasing number of protons C) Atomic number is the number of electrons, the atoms are arranged by the decreasing number of protons D) All of these
A) Supernova Nucleosynthesis B) Primordial Nucleosynthesis C) R-Process D) Stellar Nucleosynthesis
A) stable inner electrons B) valence electrons C) positron D) electrons in fully occupied orbitals
A) covalent bond B) metallic bond C) electrostatic bond D) ionic bond
A) IF5 B) PF3 C) I2 D) CO2
A) It has both polar and nonpolar covalent bonds B) It is a polar molecule C) It has zero net dipole moment D) It has one ionic bond
A) Br—Br B) Se—Br C) Li—Br D) Na—Cl
A) Polar bonds are arranged such that they cancel each other B) All bonds are polar covalent C) There is lone pair in the central atom and arranged unevenly that cause the dipole moment D) There is a polar bond present
A) To bridge the difference in polarity of two or more substances B) To make the other substance polar C) To speed up the chemical reaction without being consumed in the process D) To produce an aromatic solution
A) Molecules of a substance is uniformly distributed in water solvent B) A molecule is water-loving C) A molecule is polar D) A molecule is water-fearing
A) The unequal sharing of electrons gives the water molecule a slight negative charge near its hydrogen atoms and a slight positive charge near its oxygen atom B) The water molecule is neutral. C) The molecule has two poles, at which it is colder than other regions of the molecule. D) The equal sharing of electrons gives the water molecule a slight negative charge near its oxygen atom and a slight positive charge near its hydrogen atoms |