Measurement
When determining significant figures, if there is NO decimal present, you start from the __________ side and begin counting at the first non-zero number.
Atlantic
or
right
Protons have a _______ charge.
What is Positive?
Which scientist first determined that electrons are found outside of the nucleus?
Rutherford
Which two particles are found in the nucleus?
What are protons and neutrons?
Who discovered the solar system model of the atom?
Bohr
A tarp’s sides are measured as 3450 m and 120 m.
How would you solve for the area of the tarp?
Length times width!!
Dalton stated that atoms of different elements have _________ properties.
Different
What subatomic particle is negatively charged, quantized on energy levels around the nucleus, and have practically no mass?
What is an Electron?
This scientist is credited for the Nuclear Model of the atom.
Who is Rutherford?
What Greek philosopher originally came up with the word "Atomos" for an indivisible particle?
What is Democritus?
Scientists estimate that the Nazca Plate moves toward South America at about 7 cm each year, helping form the Andes Mountains. How far is this movement in kilometers?
0.00007 km
Thomson
What subatomic particle was discovered by Rutherford?
Proton
Who is Dalton?
Which scientist theorized that atoms have orbiting electrons that can jump energy levels?
Who is Niels Bohr?
A rectangular lab mat has length 14.23 m and width 2.6 m.
How many significant figures would you use to express the area (length times width)?
2
Always use the lowest number of significant figures on your calculations for your final answer.
Where is most of the atom's mass located?
Nucleus
In Bohr's model, orbits are called _______.
Energy levels
There were two major findings of Rutherford's Gold Foil Experiment. Name one.
The atom is mostly empty space
OR
There is a positively charged nucleus
What did Rutherford determine with the Gold Foil experiment?
The atom has a small dense positively charged nucleus, but is most empty space
While analyzing a water sample, a lab technician measures the mass of dissolved salt to be 0.0000725 g.
In proper scientific notation, the number would be written as 7.25 × _____ g
10⁻⁵
or
7.25 × 10⁻⁵ g
Name two of John Dalton's postulates of Atomic Theory:
What is:
All matter consists of indivisible particles called atoms.
Atoms can neither be created nor destroyed.
Atoms of the same element are identical in mass and properties.
Compounds are formed by a combination of two or more different kinds of atoms.
Who published a theory about atomic structure, suggesting that electrons are found only in certain energy levels?
Who is Niels Bohr?
A neutrally charge atom has the same number of these two subatomic particles:
What are protons and electrons?
What did Rutherford use to bombard the gold foil in his experiment?
Helium atoms, or alpha particles.