RelativeResourceManager;JSESSIONID=7Tb2L1vS89bnntpyxj0jtThxxG0XtBtbZhnCm7rs2Tcz6YcphDbD!1581734092!n

RelativeResourceManager;JSESSIONID=7Tb2L1vS89bnntpyxj0jtThxxG0XtBtbZhnCm7rs2Tcz6YcphDbD!1581734092!n

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
CHEMISTRY 121 1 Department of Chemistry University of British Columbia Problem Set 2 Answer The Atom, Periodic Trends and s-Block Elements 1. Calculate the atomic mass of a sample of naturally occurring boron which contains 19.9% B 10 5 and 80.1% B 11 5 . The answer is: 10.801 u Atomic mass of Boron = 10.013 × 19.9% + 11.009 × 80.1% = 10.811 u 2. Determine the number of valence electrons for the following elements: Na, Ca, P, Se, I, Xe, O, and Sb. Valence electrons are electrons in the outermost electron shell. The number of valence electron Na 1 Ca 2 P 5 Se 6 I 7 Xe 8 O 6 Sb 5 3. In which of the following groups are all the species isoelectronic? (a) Mg + , Na, Ne (b) Br - , Rb + , Sr 2+ (c) K, Ca + , Cl - (d) Be 2+ , He, Li + (e) Ba 2+ , Xe, I - The answers are: B, D and E. Species Ground state configuration Mg + , Na [Ne]3s 1 Br - , Rb + , Sr 2+ [Kr] K, Ca + [Ar] 4s 1 Cl - [Ar] Be 2+ , Li + [He] Ba 2+ , I - [Xe] 4. Consider the following atoms: Cs, Ba, S, F, and Ne to answer the following questions. (a) Which has the largest radius? (b) Which releases the greatest energy when an electron is absorbed?
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
CHEMISTRY 121 2 Department of Chemistry University of British Columbia (c) Which has the greatest first ionization energy? (d) Which has the smallest ionization energy? 4(a)
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 4

RelativeResourceManager;JSESSIONID=7Tb2L1vS89bnntpyxj0jtThxxG0XtBtbZhnCm7rs2Tcz6YcphDbD!1581734092!n

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online