A60.0-g sample of fermium-253 was placed in a sealed vessel 9.0 days ago. only 7.5 g of this isotope is now left. what is th
half-life of fermium-253?
3.0 days
4.5 days
17.5 days
20.0 days

22. a flask containing 450 ml of 0.50 m h2so4 was accidentally knocked to the floor. how many grams of nahco, do you need to put on the spill to neutralize the acid according to the following equation: h2so4(aq)+2 nahcos(aq) na,so(aq) +2 h20()+2 co2(g) d) 38 g a) 2.3 g b) 9.5 g c) 19 g

Identify one disadvantage to each of the following models of electron configuration: -dot structures -arrow and line diagrams -written electron configurations type in your answer below. (answer) -dot structures do not show the distribution of electrons in orbitals and take up a lot of space. -arrow and line diagrams take up a lot of space and make it difficult to count electrons. -written configurations make it easy to lose count of electrons and do not show the distribution of electrons in orbitals.

If two atoms are bonded to a central atom with no lone pairs,how will they be arranged