Metric System/Lab Equipment
What is the standard metric base unit used for measuring mass
The gram
What is the formula for density? Units included
D=M/V g/ml or g/cm3
What were the two elements discovered by Madame Curie?
Radium and Polonium
Cations Vs Anions. Define and give example
Cations - positively charged Na+ (lost an electron)
Anions - negatively charged Cl- (gained an electron)
Ice to water, salt dissolved in H2O
Rust on bike, bleaching teeth
What lab equipment is used to measure the volume of a liquid? What are the units to measure a liquid?
Graduated cylinder - g/mL
No! It will sink because the density is greater than 1g/cm3
Name the 3 subatomic particles of an atom, their charges, and their roles.
Proton +, identifies atom
Neutron - neutral, adds mass, creates isotopes when this # is changed
Electron - responsible for bonding and reactivity
Why are Group #17 atoms reactive?
They have 7 electrons in their valence shell - just one electron short of a full shell, they strongly pull in or share an electron to become stable
What does the kinetic molecular theory (KMT) state?
All particles of matter are in constant motion
What is the method used to determine the volume of an irregular solid? How is it done?
Water displacement method. Submerge object in water.
What is the pigment responsible for color changes due to pH called?
Anthocyanins
Magnesium is in group 2 period 3, how many electrons are in its valence shell?
A magnesium (Mg) atom lost 2 electrons, it would have a charge of ...?
2 electrons in the valence shell
Losing 2 electrons, it will be Mg2+
How are an atoms stability and reactivity related?
Inversely! higher stability= lower reactivity
lower stability = higher reactivity.
What is an example of sublimation?
solid turns to gas - air freshener in a room, dry ice releasing CO2
Convert 0.00045 Liters into centiliters (cL)
0.045cL
What does pH stand for, what is a neutral pH - and what can be said about the concentration of H+ and -OH ions?
Potential of hydrogen/power of hydrogen. a neutral pH is 7, indicates equal amounts of H+ and -OH ions
What does the mass number of an atom a total of? Is it a whole number or decimal?
The number of protons and neutrons in the nucleus. A whole number. Different isotopes of the same element have the same # protons but different # neutrons, which means they can have different mass numbers
What does the mass number on the periodic table represent for an element? Why is it a decimal and not a whole number?
The weighted average mass of all naturally occurring isotopes of that element - cant be a whole number because percentages/individual isotope masses cannot average out to be a clean number!
Why does the temperature of ice stay the same when its melting?
It stays the same (at 0°C or 32°F) while it melts because all added heat energy is used to change its state rather than to increase molecular speed
What is the mass of a solid with a density of 1.5 g/cm3 and a volume of 19 cm3? Correct units needed!
28.5 grams
All are solid cubes of equal mass, which cube would have the lowest volume?
aluminum (density = 2.7)
tin (density = 7.3)
glass ( density = 3.6)
mercury (density = 13.6)
Mercury (density = 13.6). All cubes have equal mass, the substance with the highest density will occupy the smallest volume.
Count the atoms!
2(NH2)₂Cr₂O3
Grand Total:4 + 8 + 4 + 6 = 22 atoms!
What was the name of the Greek philosopher than defined an atom as indivisible? What was the Greek word used?
Democritus. Atomos
What is the difference between an endothermic reaction and an exothermic reaction?
an endothermic reaction absorbs heat from its surroundings (its cooler than surroundings - melting ice), while an exothermic reaction releases heat into its surroundings (its hotter than its surroundings - burning wood)