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