Question

chemistry - test a - electrons in atoms
equations: c = λv & e = hv
c = 3.00×10^8 m/s h = 6.626×10^(-34) j·s

1. elements in the same group of the periodic table have the same

a. number of electrons b. number of valence electrons c. average atomic mass d. electron - configuration

1. how many electrons are in the 2nd energy level (n = 2) of an atom?

a. 32 b. 18 c. 8 d. 2

1. probabilities are used in the quantum mechanical model of the atom because of the heisenberg principle. this principle states that the precise ____ and ____ of an electron cannot be known at the same time.

a. charge, spin b. charge, velocity c. position, velocity d. charge, position

1. which statement describes the atomic emission spectra below?

hydrogen emission spectrum
a. the unique pattern of colors that is determined by the arrangement of electrons in an atom.
b. a series of colored lines that represent the origin of the atom.
c. a diagram that shows the energies of the atomic orbitals.
d. a spectrum that contains radiation from all wavelengths.

1. the electron - configuration below represents the ion of which element?

1s²2s²2p⁶ with a - 1 charge
a. potassium b. neon c. fluorine d. sodium

1. which of the following is the correct noble gas notation for titanium (atomic number 22)?

a. kr4s²3d² b. ar3d²4s² c. ar4s²3d² d. 1s²2s²2p⁶3s²3p⁶4s²3d²

1. what is the element that has the electron - configuration of ne3s²3p³?

a. phosphorus b. neon c. silicon d. barium

Explanation:

Step1: Recall periodic - table group property

Elements in the same group of the periodic table have the same number of valence electrons. So for question 1, the answer is b.

Step2: Determine electrons in energy level

The number of electrons in an energy level is given by \(2n^{2}\). For \(n = 2\), \(2n^{2}=2\times2^{2}=8\). So for question 2, the answer is c.

Step3: Understand Heisenberg Principle

The Heisenberg Principle states that the precise position and velocity of an electron cannot be known at the same time. So for question 3, the answer is c.

Step4: Interpret atomic emission spectrum

The atomic emission spectrum is a series of colored lines that represent the energies of the origin of the atom, which is determined by the arrangement of electrons in an atom. So for question 4, the answer is b.

Step5: Analyze electron - configuration for ion

The electron - configuration \(1s^{2}2s^{2}2p^{6}\) with a - 1 charge means the neutral atom has \(1s^{2}2s^{2}2p^{5}\), which is Fluorine. So for question 5, the answer is c.

Step6: Write noble - gas notation for Titanium

Titanium (atomic number 22) has the electron - configuration \([Ar]3d^{2}4s^{2}\). So for question 6, the answer is b.

Step7: Identify element from electron - configuration

The electron - configuration \([Ne]3s^{2}3p^{3}\) corresponds to Phosphorus. So for question 7, the answer is a.

Answer:

1. b. number of valence electrons
2. c. 8
3. c. position, velocity
4. b. A series of colored lines that represent the energies of the origin of the atom.
5. c. Fluorine
6. b. [Ar]3d^{2}4s^{2}
7. a. Phosphorus