BISC 220Lg Lecture Notes - Lecture 2: Valence Electron, Atomic Number, Chemical Element

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scarletminnow29

11 Jun 2020

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Chapter 2: the chemical basis of life, i: atoms, molecules, and water. Atoms: the smallest functional units of matter that form all chemical substances, cannot be further broken down into other substances by ordinary means, each specific type of atom is a chemical element. Protons: number of protons is what distinguishes one element from another, atomic number equals number of protons, also equal to the number of electrons in the atom so that the net charge is zero. Moles: 1 mole of any element contains the same number of atoms: 6. 022 x 1023, avogadro"s number. H-f: 2 pairs of electrons double bond, ex. O=o: 3 pairs of electrons triple bond, ex. Properties of water: solutes are dissolved in solvents (liquid) to form a solution. Ice floats so water is less dense at lower temperatures. Transportation of water: trees take up water from their roots.

Related Questions

ATOMIC STRUCTURE

1. A neutral oxygen atom (atomic number = 8) has 8 electronslocated in 2 different electron orbitals. TrueFalse

2. Hydrogen has only one neutron and no protons in itsnucleus. TrueFalse
3. An atom consists of a central nucleus surrounded by electronsthat are in constant motion. TrueFalse
4. Almost all of the mass of an atom is concentrated in itselectrons. TrueFalse
5. The orbital of an electron is the volume of space where theelectron is most likely to be found. TrueFalse
6. Almost all of the volume of an atom is emptyspace. TrueFalse
7. The reactivity or chemical behavior of an atom depends primarilyon the number of neutrons it has. TrueFalse
8. Modern physics indicates that we cannot determine the exactlocation of a particular electron at any giventime. TrueFalse
9. Electrons are maintained in their orbitals by their attractionto the positively charged nucleus. TrueFalse
10. Atomic orbitals represent probability distributions forelectrons and come in a variety of shapes. TrueFalse

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1. An ionic bond between two atoms is formed as a result of the ______________.

a) sharing of electrons

b)transfer of electrons from one atom to the other.

c) loss of electrons from both atoms.

d) loss of a proton from one atom

2. Choose the phrase that best completes this sentence: Microtubules ____________ and are required to pull duplicated chromosomes to opposite poles of dividing cells.

a)generate contractile forces

b)are intermediate in thickness

c)are found in especially large numbers in muscle cells

d)can rapidly reorganize

3. Which subatomic particles contribute to the atomic number for any given element?

a)protons

b)neutrons

c)protons and electrons

d)protons and neutrons

1. (TCO 1) Control subjects in a double-blindtest of a new drug are (Points : 4) informed of what drug they aregetting.
informed of what drug they aregetting but their private physicians are not.
given larger doses of thedrug.
infected with a differentdisease than the experimental subjects.
not given the experimentaldrug but are otherwise treated the same as the experimentalsubjects.

Question 2. 2. (TCO 1) My dog will eat more ofher food when I pour bacon grease over the food before I give it toher. This is an example of a(n) _____. (Points : 4)

observation
hypothesis
experiment
theory
All of the above

Question 3. 3. (TCO 1) Deductive reasoning isused to make _____ based on a hypothesis. (Points : 4)

data
theories
statistical tests
correlations
predictions

Question 4. 4. (TCO 2) Which of the followingstatements about the periodic table is incorrect? (Points : 4)

A period is a horizontal rowon the periodic table.
A group is a column on theperiodic table.
The elements in each periodhave similar chemical properties.
The A groups contain therepresentative elements.
The B groups contain thetransition elements.

Question 5. 5. (TCO 2) How do you find themass number of an atom? (Points : 4)

Add up the number of protons,electrons, and neutrons in the atom.
Add up the number of protonsand neutrons in the atom.
It is equal to the number ofprotons in the atom.
It is equal to the number ofneutrons in the atom.
Find the net electrical chargeof the atom.

Question 6. 6. (TCO 2) An isotope of potassiumhas a mass number of 39. How many neutrons are present in thisisotope? (Points : 4)

19
20
24
44
58

Question 7. 7. (TCO 2) Which particles arefound in the nucleus of an atom? (Points : 4)

Only neutrons
Protons and electrons
Protons and neutrons
Only electrons
Only protons