Science test 10/2/19
nucleus
Rutherford predicted that an atom has a dense core called a _______
carbon has 6 protons, 6 electrons, and 6 neutrons and boron has 5 protons, 5 electrons, and 7 neutrons
a carbon atom has an atomic number of 6, and a boron atom has an atomic number of 5. an atom of carbon-12 has the same mass number of boron-12. sketch molecules that show the difference in the two atoms
number of valence electrons
all the elements in group 2 have the same...
group 18 are the only elements with 8 valence electrons the element in period 5 with 8 valence electrons is xenon
an element in period 5 has eight valence electrons. use the periodic table to figure out which element this is. explain why you chose this element
non metal
density- low; conductivity- low; appearance- dull; mallability- low; ductility- low; this element is more likely to be a _________________
by increasing atomic number
how are the atoms arranged in the modern periodic table?
8
how many valence electrons are present in an atom of argon?
density, conductivity, appearance, malleability, and ductility
if you were given 5 unknown substances and were asked to describe them by their physical properties, what would you look for? what should you not do while observing for physical properties?
8
most atoms gain, lose, or share electrons to end up with how many valence electrons?
semi conductors
one property of metalliods not shared with metals or nonmetals is the metalloids are ________________
particle excelerator
scientists learn about the properties of some particles from the collisions that occur inside ________________________
acid and base
the products of a neutralization reaction are ...
chlorine and iodine
use the periodic table to choose the pair of elements whose properties are most similar
feels slippery
what is a property of a base?
a plastic bottle
what is most likely to be damaged by an acid?
polar
when a molecule has slight positive and negative charges at different locations, the molecule is ___________
when they share electrons
when do atoms form a covalent bond?
neutron
which atomic particle has no charge?
chlorine -35, chlorine -37
which pair of atoms are isotopes?
one type of atom cannot be changed to another type by a chemical reaction
which statement is part of Dalton's atomic theory
mendeleev
who organized elements into the modern periodic table?
valence electrons are free to move
why do metals have high conductivity?
