1) What is the energy of: a) A gamma ray photon of frequency 5.00 x 1015 Hz? b)

Question

1) What is the energy of:

a) A gamma ray photon of frequency 5.00 x 1015 Hz?

b) A microwave photon of wavelength 1.00 mm?

2) A star is 1012 light years away from Earth. During what event in history did the light now arriving at Earth leave the stars?

3) A 1500 W hair dryer is operated on a 120 V circuit for 10 minutes every day. If electricity costs $0.15/kWh:

a) What is the cost of operating the blow dryer for 1 day?
b) What is the cost of using the blow dryer for 1 year (365 days)?


4) Write balanced chemical equations for the following unbalanced reactions:

a) SO2 + O2 SO3

b) Mg(OH)2 + H3PO4 Mg3(PO4)2 + H2O



5) Write a nuclear equation for the following decay reactions:

a) Alpha decay:

239
94


b) Beta decay:


241
94

Explanation / Answer

a) energy = hV where v = 5.00 x 1015 Hz and h = plancks constant

b) energy = hc/ , c = speed of light

2) t = 1012*365*24*60*60*(speed of light)

3)cost of operating the blow dryer for 1 day = 1500*1/6 * 0.15

cost of using the blow dryer for 1 year (365 days) = 1500* 365*24*0.15

4)a) SO2 +1/2 O2= SO3

b) 3Mg(OH)2 + 2H3PO4 = Mg3(PO4)2 +6 H2O

for alphadecay check net there it is clearly given

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.