Periodic Trends
What is one of the 2 factors that affect periodic trends?
# of protons/electrons (electrostatic attraction)
# of energy levels (electron shielding)
What is the equation that shows the relationship between the speed of light, wavelength, and frequency?
c= lamda nu (upside down y and weird v)
If I am converting from meters to centimeters, and I am using the conversion 100 cm = 1 m, does the 1 meter go in the top of the next fraction or in the bottom of the next fraction? (I can show you what I mean if you need me to)
bottom
What kind of zero is present in the number below? Is it significant?
5407
Sandwiched, yes
Henrietta is sick and takes her temperature 3 times with the following results: 76 degrees, 78 degrees, 77 degrees
Her true temperature is 91 degrees
Was her data precise? Was it accurate?
Yes precise, not accurate
Which periodic trend(s) increase as you go up a column and to the right across a period?
Options: Atomic Radius, Electronegativity, Ionization Energy
Electronegativity and Ionization Energy
What is the speed of light?
a. 9.8 m/s
b. 3.0 x 108 m/s
c. 6.626 x 10-28 m/s
b. 3.0 x 108 m/s
How many inches are in .41 feet?
Put in proper sig figs
4.9
How many sig figs are in the number below:
980.00
5
Henrietta is sick and takes her temperature 3 times with the following results: 76 degrees, 102 degrees, 93 degrees
Her true temperature is 90 degrees
Was her data precise? Was it accurate?
Not precise, but accurate
Rank the following elements in order from biggest to smallest:
Nitrogen, Carbon, Boron
Boron, Carbon, Nitrogen
What is the unit for frequency?
Hertz
How many feet are in 4.26 miles? (1 mile = 5,280 feet) Put your answer in proper sig figs
22492.8 --> 22,500
Which kinds of zeros are significant?
Trailing with decimal, trailing without, sandwich, leading
Trailing with decimal, sandwich
Which reading is more precise?
97.1 degrees
97.105 degrees
97.105 degrees
Explain the trend for electronegativity and the REASON for the trend being the way it is.
Trend: increases to the right and up
Reason: increased # of electrons increases electrostatic attraction and lower numbers of energy levels means less electron shielding
What is the frequency of a wave with a wavelength of 5.43 m? (must be correct # of sig figs and the right unit)
5.52 x 107 Hertz
or
55,200,000 Hertz
Convert 5.16 m/s to km/min
(1000 m = 1 km)
0.310
How many significant figures are in the number below:
0390020
5
What does percent error measure?
How accurate a value is/how close the value is to the accepted value
Which element has a higher 1st ionization energy and why?
Germanium or Silicon
Silicon
It has fewer energy levels and therefore less shielding, so it will require more energy to remove the electron
What is the wavelength of a wave if it has an energy of 625 J?
E= h v
c= lamda v
h= 6.626 x 10-34
c= 3.0 x 108 m/s
3.18 x 10-28 m
Convert 8.714 mi/day2 to ft/hr2
(1 mile = 5,280 ft)
Put in proper sig figs
79.88
Provide a number that has 4 sig figs and includes at least 2 different types of zeroes
Depends on student answer
Carl experimentally determines a density value to be 56.1 g/cm3 and the actual value should have been 58.4 g/cm3
What is his percent error?
4%