The atomic number of re is 75. the atomic mass of one of its isotopes is 186. how many neutrons are in an atom of this isotope?

a. 186

b. 111

c. 261

d. 75

What is an element in the alkali metal group

4 When an excited electron in an atom moves to the ground state, the electron (1) absorbs energy as it moves to a higher energy state (2) absorbs energy as it moves to a lower energy state (3) emits energy as it moves to a higher energy : state (4)

1. What is a source of new alleles in natural populations?

Carbon-14 has a half-life of 5730 years. In a plant fossil, you find that the 14C has decayed to 1/4.00 of the original amount. How long ago was this plant alive?

What is the relationship between urbanization and population increase

A chemical reaction can start when enough activation energy is added to the reactants. Do you think the activation energy for chemical reactions in living things is high or low / Explain your answer

20 Which statement describes a reversible reaction at equilibrium? (1) The activation energy of the forward reaction must equal the activation energy of the reverse reaction.

Count the total number of atoms in CaCO3: 2 3 4 5 6

Question #21TrueFalse The general name for a substance added to a reaction that affects the rate but is not consumed in the reaction is called a complex a. True b. False

what kinda energy is produced when a force causes a substance to vibrate, and the energy is transferred through the substance in a wave.