P1 Flashcards
What was John Dalton’s model of the atom?
It was a small, indestructible sphere and that all the atoms in an element are the same. All atoms in one element are different from the atoms in all the other elements.
What was J.J. Thompson’s version of the particle model?
He thought of the plum pudding model and that an atom contains negative electrons and the atoms are overall neutral.
What was Rutherford’s model of the atom?
He suggested that an atom had a tiny, heavy and positively charged nucleus and that almost all of the mass is in the nucleus
How did Rutherford get to his version of the model?
He fired alpha particles at gold foil expecting them all to go straight through but a tiny amount of alpha particles bounced back or changed direction.
What is the Bohr model of the atom?
He suggested that electrons can only move in fixed orbits called electron shells
What is the diameter of an atom?
1 x 10(-8)
What is the length of a molecule?
1 x 10(-10)
Who helped Rutherford during the alpha particle experiment?
Hans Geiger and Ernest Mardsen
What is the formula for density?
Mass (Kg)
—————-
Volume (m^3)
What is the law of conservation of mass?
Particles cannot be created or destroyed, only transferred
What is 273 degrees kelvin in Celsius?
0
What is the difference between energy and temperature?
You transfer energy from the chemical store of a fuel to the thermal store of the substance being heated. The particles move or vibrate more but individual particles don’t get hotter.
What happens when you heat things up?
Change the energy stored within the system to increase the temperature
Produce a change of state
Make chemical reactions happen
What is specific heat capacity?
The energy needed to raise the temperature of 1kg of a material by 1k
What are the units for specific heat capacity?
Joules per Kilogram Kelvin/Celsius (J/Kg K/C)
