Chemistry: Unit 2 Exam
How many electrons does Si contain?
14
An atom has an atomic number of 15 and a mass number of 31. How many protons are there in the atom?
15
What electron configuration matches an oxygen atom?
1s2 2s2 2p4
What is the electron configuration for a Sulfur atom?
1s2 2s2 2p6 3s2 3p4
How many electrons can the first energy level hold?
2
How many valence electrons does Si contain?
4
How many orbitals are in the 4f sublevel?
7 orbitals
The electron configuration of an atom is 1s2 2s2 2p6. The number of valence electrons in the atom is
8
The atomic number of an element that has 9 protons, 9 electrons, and 10 neutrons is __
9
Which is the smallest in size? a. N b. S c. I d. Fr
N
In order for an atom to be neutral what has to be true?
The atom has the same number of protons and electrons
What atom matches this electron configuration?1s2 2s2 2p6 3s2 3p6 4s2 3d10?
Zinc
Where is most of the mass in an atom located?
in the nucleus
9. electrons have this type of charge?
negative
4. Particles in an atom that are neutral and have no charge are
neutrons
2. the central region of an atom where its neutrons and protons are is it
nucleus
Which of the following determines the identity of an element?
number of protons
6. The positive particles of an atom are
protons
Most of the mass in an atom is made up of __
protons and neutrons
What does the C represent?
chemical symbol
How many orbitals are in the 4s sublevel?
1 orbital
The electron configuration of an atom is 1s2 2s2 2p6. The number of electrons in the atom is
10
If an atom has 12 positiwly charged subatomic particles, which of the following must it also have to be considered a neutral atom?
12 electrons
An orbital can at most hold how many electrons?
2 electrons
An atom has 10 protons, 15 neutrons and 10 electrons what is it mass number.
25
5. What is the atomic number for an element with three protons?
3
How many orbitals are in the 4p sublevel?
3 orbitals
After filling 5s, electrons would fill...
4d
After filling 6s, electrons would fill
4f
How many orbitals are in the 4d sublevel?
5 orbitals
3. an atom with atomic number 6 would have how many protons
6
An element with a mass number of 11 and an atomic number of 5 has how many neutrons?
6
7. The smallest particle of any particular type of matter is known by which of the following terms?
Atom
What atom matches this electron configuration?1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d9?
Gold
Which of the following is the smallest in size? a. K b. Na c. Li d. Cs
Li
What atom matches this electron configuration?1s2 2s2 2p6 3s2?
Magnesium
What subatomic particles would you find in the nucleus of an atom?
Protons and Neutrons
How is the number of neutrons in the nucleus of an atom calculated?
Subtract the number of p+ from the mass number
1. all matter is made of what
atoms
Which subatomic particles contributes the most to the mass of an atom?
d. protons and neutrons
8. What is the mass number?
the number of protons and neutrons
What is the atomic number?
the number of protons in the nucleus
