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