Draw the Lewis structure for BH3. 1. Identify if the octet rule is not obeyed. 2. State which atom doesn't follow the octet rule. 3. State how many electrons surround this atom.

Which statements are true about electronegativity? (a) Electronegativity increases from left to right in a period of the Periodic Table. (b) Electronegativity increases from top to bottom in a column of the Periodic Table. (c) Hydrogen, the element with the lowest atomic number, has the smallest electronegativity. (d) The higher the atomic number of an element, the greater its electronegativity.

Successive substitution of F atoms for H atoms in the molecule NH3 produces the molecules NH2F, NHF2, and NF3. a. Draw Lewis structures for each of the four molecules. b. Using VSEPR theory, predict the geometry of each of the four molecules. c. Specify the polarity (polar or nonpolar) for each of the four molecules.

Draw Lewis structures showing all valence electrons for these molecules. (a) C2H6 (b) CS2 (c) HCN

What is the most polar bond in the molecule?

Use Lewis symbols to show the reaction of atoms to form hydrogen selenide. H2Se. Indicate bonding pairs and lone pairs in the electron-dot formula of this compound.

Step 1 – Write the Lewis structure from the molecular formula.Step 2 – Assign an electron-group arrangement by counting all electron groups (bonding plus nonbonding) around the central atom (or around each centralatom, if more than one central atom in structure).Step 3 – Predict the ideal bond angle from the electron-group arrangement and the effect of any deviation caused by lone pairs or double bonds.Step 4 – Name the molecular shape by counting bonding groups and nonbonding groups separately.Step 5 – Predict whether the molecule is polar or nonpolarStep 6 – Describe the hybridization around the central atom and identify the total number of σ and π bonds in the structure

1. Considering ionic compounds, a) What type of elements tend to form cations and why? b) What type of elements tend to form anions and why? c) What is the formula for aluminum oxide? Describe or show what happened to the valence electrons of each atom to make the compound. 2. Considering molecules and covalent bonding, a) Draw the Lewis structure of SO2 that obeys the octet rule. (Draw this out on paper, take a photo, and embed this image into the document you will submit). b) Label on your structure which electrons are bonding and which are nonbonding. c) What is the molecular shape of this molecule? d) Look up the electronegativities of these two elements in Figure 4.5 of the text. Would you expect this molecule to be polar or nonpolar? Why? 3. What is molecular recognition, how is it used to create medicines and materials, and why is it advantageous to use this in the manufacturing new drugs and medicines? 4. Carbon dioxide in the atmosphere has been a topic in the news lately as…

* If two or more atoms have the wrong number of valence electrons around them, just enter the chemical symbol for the atom as many times as necessary. If two oxygen atoms have the wrong number of electrons around them, enter the symbol O twice.

Use Lewis theory to determine the chemical formula for the compound formed between Ca and N. Ca3N2 Ca₂N3 CaN₂ CaN