Chapter 2 Flashcards
the law of conservation of mass states that in a chemical reaction, ___________ is neither created nor destroyed
matter
the law of definite proportions states that all samples of a given compound, regardless of their source or how they were prepared, have the same proportions of their constituent ____________
elements
the law of multiple proportions states that when two elements form 2 different compounds, the masses of element B that combine with 1g of element A can be expressed as a :
ratio of small whole numbers
most of the atom’s mass and all of its positive charge are contained in:
small core called nucleus
most of the volume of the atom is:
empty space through which the tiny, negatively charged electrons are dispersed
there are as many negatively charged electrons outside the nucleus as there are positively charged particles (protons) inside the nucleus, so that matter of a pure atom is:
electrically neutral
isotopes are still the same element and have very similar chemical and physical properties, except _________
density
[isotope with more neutrons is more massive = higher density]
what are ions?
elements with charge (when a neutral element loses or gains electrons)
Cations VS anions
cation= positive ion
anion= negative ion
On the periodic table, group 17 are:
Halogens
Halogens commonly form:
-1 ions
Group 18 of periodic table are:
noble gases
Noble gases are:
always neutral [0 charge] , unreactive
Group 1 of periodic table are:
alkali metals
Alkali metals are:
very reactive; form +1 ions
