Blood storage. Blood stored at 4.0 ∘C lasts safely for about 3 weeks, whereas blood stored at -160 ∘C lasts for 5 years. Express 4.0 ∘C on the Fahrenheit and Kelvin scales.

Which of the following conditions lead you to see an absorption line spectrum from a cloud of gas in interstellar space? the cloud is extremely hot. the cloud is visible primarily because it reflects light from nearby stars. the cloud is cool and lies between you and a hot star. the cloud is cool and very dense, so that you cannot see any objects that lie behind it.

Explain the difference in reactivity of the elements based on their electron configurations.

3. a particle with initial velocity v⃗ 0=(5.85×103m/s)j^ enters a region of uniform electric and magnetic fields. the magnetic field in the region is b⃗ =−(1.35t)k^. you can ignore the weight of the particle. a. calculate the magnitude of the electric field in the region if the particle is to pass through undeflected, for a particle of charge +0.640 nc.