A
What is the chemical symbol for Sodium?
Na
What is the name for group 7 in the periodic table?
The name for the element with symbol K?
Name any of the three subatomic particles
PROTONS or NEUTRONS or ELECTRONS
What is the atomic number of lithium?
3
What charge do electrons have?
-1 (negative)
Which subatomic particle has almost no mass?
electrons
Where in the atom are neutrons found?
nucleus
Which periodic table group is unreactive?
Group 8 - Noble Gases
What is the atomic number of uranium?
92
Which two subatomic particles does the mass number tell us about?
protons and neutrons
Which element is more reactive? He or Br?
Br (its a halogen)
Which side of the periodic table are gases mostly found on? (left or right)
Right
Which element has more protons? Lithium or Chlorine?
Chlorine (has a higher atomic number = more protons)
What do we call an atom that has a charge?
Ion
How many electrons does a neutral sodium atom have?
11
75% of Chlorine is found as Chlorine-35. 25% of Chlorine is found as Chlorine-37. What is the relative atomic mass?
35.5
(35x75)+(25x37) /100
The number of which two subatomic particles must be the same for an atom to be neutral?
Electrons and protons
An atom has atomic number 5 and mass number 11, how many neutrons does it have?
6
A chlorine atom always has the same number of which subatomic particle?
protons
What is an isotope?
Atoms of the same element with different numbers or neutrons (or different mass numbers)
How many electrons does a sodium atom with a charge of +1 have?
10
(A neutral sodium atom has 11, but +1 tells us there is 1 more proton than electrons, so we can only have 10 electrons)
Uranium has an atomic number of 92 and a mass number of 238. How many electrons does it have?
92
Silver has two isotopes. One has a mass number of 107 and the other has a mass number of 109.
The relative atomic mass of silver is 108.
What does this tell you about the percentage of each isotope in silver?
50% of each isotope
How many electrons are in a chlorine atom with a mass number of 37 and a charge of -1.
18
Atomic number of chlorine is 17, -1 charge means one extra electron.