Chemistry Midterm Review

Explain the difference between fission and fusion Fission is splitting of a big nucleus into 2 smaller ones Fusion is combining 2 nuclei to make one bigger one

Write a balanced decay equation for the decay of Pb-210 Beta decay forming Bi-210

A sample of I-131 decays to 1 g in 40 days A sample of I-131 decays to 1 g in 40 days. What was the mass of the original sample? 1g 2g 4g 8g 16g 32g 40 32 24 16 8 time 0

Write the symbol, mass and charge for the alpha, beta and gamma particles Alpha mass = 4, charge = 2 Beta mass = 0, charge = -1 Gamma mass = 0 charge = 0

Nuclear reactions release large amounts of energy. Why? Mass is converted to energy

Name the 5 types of reactions Synthesis Decomposition Single replacement Double replacement combustion

Complete and balance the following reaction: sodium chloride and barium 2 NaCl + Ba 2 Na + BaCl2

What 2 products always form in a combustion reaction? Carbon dioxide water

Balance and Identify the type of reaction: Chromium and oxygen yields chromium (III) oxide 4Cr + 3 O2 2 Cr2O3 synthesis

If it has mass and takes up space it is called…. matter

How many e- pairs in and F orbital? 7

Draw Lewis Dot structure of N and C

What element is represented by [Ne] 3s2 3p4

How many neutrons are in Se-79? 45

What were 2 conclusions from Rutherford’s Gold Foil Experiment? Atoms have small dense + charged nucleus Atoms are mostly empty space

Draw orbital notation for e- in oxygen atom 1s2 2s2 2p4

How many valence e- are in gold and what orbitals are they in? 6s1 or 6s2

The first element to contain a pair of e- in a d orbital is: Ti

Isotopes of B are B-11 (80. 2%) and B-10 (19. 8 %) Isotopes of B are B-11 (80.2%) and B-10 (19.8 %). Show set up for calculating ave atomic mass (11 x 80.2) + (10 x 19.8) ______________________ 100

Which atom has the smallest radius: Cs, Fr, Ba, Ra, and explain why Ba, because Ba has more protons than Cs, pulling e- closer and making it smaller Ba also has less energy levels than Ra

What is the definition of atomic radius? One-half the distance between the nuclei of 2 adjacent atoms

Name the 3 types of elements on the periodic table Metals, non metals, and metalloids

List 3 properties of metals Malleable, ductile, Conductors luster

List 2 properties of non metals Brittle Poor conductors No luster

Which group contains elements in all 3 phases of matter at room temperature? 17

The elements in the modern Periodic Table are arranged according to: Atomic number

Describe the ionization energy of metals: low

What happens to atomic radius from left to right across a period? Why? Radius gets smaller because more protons pull electron closer in

Which element has an ionic radius that is larger than its atomic radius? K, Zn, Cl, Cr

Define electronegativity An element’s ability to attract e- in a compound

Which element has the largest atomic radius: Li, O, C, F, N? Why? Li, because the others have more protons pulling e- in closer

What is the trend in ionization energy as you go across period 3? Why? Increases, because more protons pulling on e-

What is the trend in ionization energy as you go down group 16? Why? Decreases, because of shielding, e- farther from nucleus and easier to remove

What intermolecular force acts on molecules of hydrogen gas? Van Der Waals

Which bond has the greatest ionic character: Al-F, C-O, K-Br, C-N?

Use poetic language to describe the metallic bond Positive ions immersed in a sea of mobile electrons

Give an example of a polar covalent bond H-Cl

Ionic bonds form between what two types of elements? Metal and non metals

What are the 7 diatomic elements H, O, N, F, Cl, Br, I

When does hydrogen bonding occur? + N, O or F

Draw a Lewis Dot structure of calcium fluoride

Draw a Lewis dot structure of the ammonium ion

What kind of bond will form between H and N? Polar covalent

Write formula for Cobalt (III) fluoride CoF3