Nuclei
A species of atom having the same number of protons in its atomic nuclei.
What is an element?
What are Sulfur and Carbon?
the smallest unit of ordinary matter that forms a chemical element
What is an atom?
Name of the group of elements with 7 valence electrons.
What are the Halogens?
a material made up of two or more different Chemical substance/substances which are not chemically combined.
What is a mixture?
The approximate mass of a proton or a neutron. (include the appropriate unit)
What is one atomic mass unit?
Elements in the same column of the periodic table have this in common.
What are the same number of valence electrons?
Protons + Neutrons = ??
What is atomic mass?
Shiny, soft, highly reactive metals at standard temperature and pressure and readily lose their outermost electron to form cations with charge +1. They can all be cut easily with a knife due to their softness, exposing a shiny surface that tarnishes rapidly in air due to oxidation by atmospheric moisture and oxygen. Because of their high reactivity, they must be stored under oil to prevent reaction with air, and are found naturally only in salts and never as the free elements.
What are the alkali metals?
An electrically neutral group of two or more atoms held together by chemical bonds.
What is a molecule?
The main place in the Universe where nuclear fusion occurs.
What are stars?
The atomic number of the most abundant element in Earth's atmosphere.
What is 7?
Element that typically has five neutrons.
What is Beryllium?
The atomic numbers of the two most common elements in the Universe.
What are 1 and 2?
a measure of a substance's resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness"
What is viscosity?
the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford based on the 1909 Geiger–Marsden gold foil experiment.
What is the atomic nucleus?
The number of valence electrons a neutral Helium atom has.
What is two?
The number of electron energy levels Arsenic has.
What is four energy levels?
Reactive element found in its free form in Earth's atmosphere due to photosynthesis.
What is oxygen?
Any quality of a substance that can be established only by changing the substance's chemical identity.
What is a chemical property?
The number of neutrons in Uranium-238.
What is 146 neutrons?
238-92 = 146.
each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties
What are isotopes?
Unreactive group in the periodic table with full outer shells of valence electrons.
What are noble gases?
a Russian chemist who published the first recognizable periodic table in 1869
Who is Mendeleev?
A broad, natural explanation for a wide range of phenomena. They are concise, coherent, systematic, predictive, and broadly applicable, often integrating and generalizing many hypotheses.
What is a scientific theory?