Chem Fall Final Review #3 (AAM & Atoms)

24.1% of all the isotopes of a an element have a mass of 75.23 amu, 48.7% have a mass of 74.61 amu, and 27.2% have a mass of 75.20 amu.
What is the average mass of this element?

• 74.92 amu
• 24.97 amu
• 75.01 amu
• 74.51 amu

An element with 4.35% have a mass of 49.95 amu, 83.79% have a mass of 51.94 amu, 9.50% have a mass of 52.94 amu, and 2.36% have a mass of 53.94 amu.

• 51.99 amu
• 52.19 amu
• 53.45 amu
• 17.33 amu

4.35% of all X atoms have a mass of 39.95 amu. 83.79% have a mass of 41.94 amu, 9.50% have a mass of 42.94 amu, and 2.36% have a mass of 43.94 amu. What is the average atomic mass of atom X?

• 41.97 amu
• 42.19 amu
• 10.43 amu
• 40.04 amu

An isotope has three forms.  30% have a mass of 4 amu, 20% have a mass of 5 amu and 50% have a mass of 3 amu.  Average atomic mass will be closest to

• 2 amu
• 3 amu
• 4 amu
• 5 amu

An element has two naturally occurring isotopes. One is 10.01 amu and is 19.9% abundant. The other is 11.01 amu and is 80.1% abundant. What is the average atomic mass? What element is it?

• 9.012, Beryllium
• 12.011, Carbon
• 6.941, Lithium
• 10.812, Boron

Tags

NGSS.MS-PS1-1

If X is the symbol for an element, which of the following two symbols represents isotopes of the same element?  
A. ⁷⁷₃₅X  B. ⁷⁷₃₃X  C. ⁸¹₃₇X  D. ⁸¹₃₅ X

• A and B

• C and D

• A and D

• A and C

The atomic number of an element determines the number of which subatomic particle?

• Neutrons

• Electrons

• Protons

• Nucleus

The smallest particle of an element that retains the properties of that element is a(n) ____.

• Atom

• Neutron

• Proton

• Electron

All atoms are ____.

• positively charged, with the number of protons exceeding the number of electrons

• negatively charged, with the number of electrons exceeding the number of protons

• neutral, with the number of protons equaling the number of electrons

• neutral, with the number of protons equaling the number of electrons, which is equal to the number of neutrons

The nucleus of an atom is ____.

• the central core and is composed of protons and neutrons

• positively charged and has more protons than neutrons

• negatively charged and has a high density

• negatively charged and has a low density