Unit 1
How many significant figures are in 0.0000094300?
5
Is digesting an apple a chemical or physical change?
Chemical Change
What are the charges of protons, neutrons, and electrons?
positive, neutral, negative
What is the group called with 7 electrons?
Halogens
How many valence electrons does Phosphorus have?
5 valence electrons
Convert 69420 g to kg
69.420kg
Is cocoa powder mixed into milk a homogeneous or heterogeneous mixture?
Homogeneous mixture
Matter can gain or lose energy only in small,specific amounts called___.
quanta
Energy required to remove an electron from an atom is called ___.
Ionization Energy
Which of the 3 Intermolecular forces has the greatest attraction
Hydrogen Bonding
If the mass is 130g and the volume is 100mL, what is the density?
1.3g/mL
What is the difference between a solute and solvent?
A solvent is the base liquid and the solute is the liquid that’s mixed in.
What is the speed of light?
3.0 x 10^8 m/s
Why are noble gases considered the most stable group of elements?
Because they have a full valence shell
Identify the molecular geometry of H20 and why?
It is a Bent because it has 2 lone pairs and bonds.
If the experimental value is 235g, and the accepted value is 310g, what is the percent error?
24%
Why does matter expand when heated?
The atoms vibrate and push away from each other.
Write the electron configuration of Germanium.
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p2
Why does the atomic radius increase as you move down a group and decrease as you move across a period?
The atomic radius increases as you move down a group because there are more energy levels, making the size of the atom bigger. The atomic radius decreases in size across the period because electrons are added to the same outer energy level while the number of protons increases, causing the atom to shrink instead of expand.
Draw a Lewis Dot Structure of SiCl4 (Silicon tetrachloride). State how many valence electrons and lone pairs it has.
32 Valence Electrons, 0 lone pairs.
What is the difference between precision and accuracy?
Precision is how close the values are to each other while accuracy is how close the value is to the accepted value.
What is the difference between a compound and mixture?
A compound is a substance made of two or more elements bound together by a chemical change. A mixture is physically combining two substances without changing the chemical composition.
Explain the relationship between energy and wavelength
The higher the energy, the shorter the wavelength. The lower the energy, the longer the wavelength.
Why does the increasing nuclear charge down a period not cause a decrease in atomic radius?
Electron shielding acts as a barrier, blocking the positive charge from the nucleus to the outer shell.
Explain Intermolecular Forces' Impact on liquids and name the 3 types.
Intermolecular Forces keep liquid molecules together and prevent them from spreading apart like gas molecules. The 3 types are Dipole-dipole, Hydrogen bonding, and London Dispersion Forces.