Chapter 3 & 24 Jeopardy Review

3-3 3-4 24 Work it

200 200 200 200

400 400 400 400

600 600 600 600

800 800 800 800

1000 1000 1000 1000

3-3200

• Name the three subatomic particles and give their charges.– Protons +, neutrons 0, electrons -

3-3400

• How is the atomic mass calculated? Where is it written in the complete chemical symbol– Atomic mass = protons + neutrons– Written in the upper left hand side of

the symbol

3-3600

• What is the atomic number? How is it unique? Where are they written in the complete chemical symbol– The number of protons.– The atomic number (protons)

identifies the element.– Lower left corner of the symbol

3-3800

• Isotopes of the same element will have different numbers of ________ and therefore _____ _______?

• How is the charge of an ion calculated? Where is it written in the complete chemical symbol– Neutron and mass numbers– P-e. Upper right corner of symbol

3-31000

• Why do elements on the PT have mass numbers with decimals?

• Give the formula to calculate the average atomic mass– The masses are weighted averages of

that elements isotopes

– (M1 x %/100) + (M2 x %/100) + ………..

3-4200

• What is the name of the force that overcomes the repulsion between protons in the nucleus?– Strong Nuclear Force

3-4400

• Which substance would be found at the bottom of a density column the most or the least dense substance?

• Why?– Most dense will be found at the bottom

of the column– The particles are closer together

creating a higher mass per volume

3-4600

• What would you guess to be the most common isotope of Silicon?– Si-28

3-4800

• What would you guess to be the most common isotope of potassium? Are you certain that is true– K – 39– No it could be calculated at 39.10

with different isotopes

3-41000

• Discuss the difference between an isotope and an ion?– Isotopes of the same element- vary in

neutrons and atomic mass, but will have the same number of protons

– Ions- have gained or lost electrons giving them a negative or positive charge calculated by #p - #e

24-1200

• What is meant by the term half-life?– The amount of time needed for half of

a radioactive sample to decay

24-1400

• The half-life of Iodine-126 is 13days. If a sample is 52 days old and now contains 2.56 g, how many grams were present in the original sample?– 41.0g (40.96 rounded correctly)

24-1600

• The half-life of carbon-14 is 5730 years. If a C-14 sample is 28,650 yrs old and originally contained 126.8grams how much is now present?– 3.963 g

24-3800

• The half life of sodium is 1.00 minutes. How much of a 3.00 g sample of sodium would remain after 10 minutes?– 0.00293

24-31000

• Discuss the concept of “Mass Defect”– Matter is not conserved during

nuclear reactions. Some matter is converted to energy. Lost mass can be calculated with the formula E = mc2

Work it200

• There are two isotopes of carbon. C-12 and C-14. Which isotope is more abundant and how do you know?– C-12 is more abundant. The average

atomic mass on the periodic table is 12.01amu, since this is a weighted average of the two isotopes C-12 must be more abundant because the averaged mass is pulled closer to it.

Work it400

• Calculate the average atomic mass of Ar with isotopes 0.337% 38Ar, 0.063% 39Ar and 99.60% 40Ar– (38 x 0.00337) + (39 x 0.00063) +

(40 x 0.9960) = 39.99 amu

Work it600

• Calculate the Average atomic mass of Ne if its isotopes occur as 90.92% 20Ne, 0.257% 21Ne and 8.82% 22Ne?– (20 x 0.9092) + (21 x 0.00257) +(22

x 0.0882) = 20.18 amu

Work it800

• Calculate the number of protons, electrons and neutrons in F-19 atom. In Cs-133 atom. In Fe3+ ion– P = 9, e = 9, N = 10– P = 55, e = 55, N = 78– P = 26, e = 23, can’t calculate the

neutrons without the mass

Old School1000

• Calculate the mass of a fish tank with the measurements of 138 cm x 122cm x 336 cm. The density of water is 0.998g/ml– M = D x V– 5650000g or 5.65 x 106 g

Final Jeopardy

• What is the formula for density?– D=m/v.