Which of the following groups contains reactive elements that need to gain only one electron to have a full outer energy level?

alkali metals

alkaline earth metals

halogens

noble gases

How many grams of iron can be made from 16.5 grams of fe2o3

What best explains the type of energy present in the wheels of a moving bus

The elements in Group 8A of the periodic table are called noble gases. Can you suggest what "noble" means in this context?

How is energy related to the change of state represented by the model? a. Atoms gain energy as a solid changes to a gas. b. Atoms gain energy as a liquid changes to a gas. c. Atoms lose energy as a solid changes to a gas. d.

Compare an ionic and a molecular compound in terms of how each is formed

What element is represented by the following electron configuration: 1s22s22p63s23p64s23d4 Question 2 options: Cr Ca Ge Ar

He substance, cocl2, is useful as a humidity indicator because it changes from pale blue to pink as it gains water from moist air. What is its name?

The weighted average atomic mass of an element depends upon the a. relative abundance of protons in the element b. mass and relative abundance of each isotope of that element c. mass and relative abundance of each neutron of that element d.

What part of an atom do we change for isotopes

The Safe Drinking Water Act (SDWA) sets a limit for mercury-a toxin to the central nervous system-at 0.002 mg/L. Water suppliers must periodically test their water to ensure that mercury levels do not exceed 0.002 mg/L.