J.J. Thomson's work with the cathode ray tube led him to discover...
Negatively charged particles (electrons) with very little mass
15
Compared to protons, neutrons have...
No charge and about the same mass.
15
What element is pictured here?
Boron
15
What is the mass number of this atom?
11
15
Is this atom neutral? Why?
Yes, because it has the same number of protons and electrons.
15
What is the atomic number of this atom?
5
15
An iron nail with a mass of 2.3 g sits in a chamber of oxygen until rust (iron oxide) forms. After the reaction, the rusted nail has a mass of 2.8 g. What mass of oxygen must have reacted?
0.50 g of oxygen
15
An iron nail with a mass of 2.3 g sits in a chamber of oxygen until rust (iron oxide) forms. After the reaction, the rusted nail has a mass of 2.8 g. What is the percent composition of iron in this rust?
82% Iron
20
What element is atom A?
Sodium
15
What is the mass number of atom B?
7
15
Which atom is an isotope of atom B?
D
15
Why isn't it possible to have an isotope of Cadmium-112.41?
112.41 is the atomic mass, an average of all isotopes. Isotopes would have a whole numbered mass.
20
In a neutral atom, what 2 subatomic particles are equal to the atomic number?