(Blank)
An atom has 6 protons, 6 neutrons, and 6 electrons. What element is it?
A. Oxygen
B. Carbon
C. Nitrogen
D. Helium
B. Carbon
Which particle contributes most to an atom’s mass?
A. Electrons
B. Protons and neutrons
C. Only protons
D. Only neutrons
B. Protons and neutrons
Where are electrons located in an atom?
A. In the nucleus
B. In orbitals/energy levels around the nucleus
C. Inside protons
D. In neutrons
B. In orbitals/energy levels around the nucleus
An atom with atomic number 12 has how many protons?
A. 6
B. 12
C. 24
D. 14
B. 12
Which statement about isotopes is correct?
A. They have different atomic numbers
B. They have different chemical properties
C. They have the same number of protons
D. They have the same number of neutrons
C. They have the same number of protons
What happens to an atom when it loses an electron?
A. Becomes neutral
B. Becomes a negative ion
C. Becomes a positive ion
D. Changes element
C. Becomes a positive ion
What is the charge of an atom with 8 protons and 10 electrons?
A. +2
B. -2
C. +8
D. 0
B. -2
What is the atomic number of an element equal to?
A. Number of neutrons
B. Number of protons
C. Number of electrons + neutrons
D. Total mass
B. Number of Protons
Which change would create an isotope of an atom?
A. Adding an electron
B. Removing a proton
C. Adding a neutron
D. Removing an electron
C. Adding a neutron
An atom becomes a +2 ion. What happened?
A. It gained 2 electrons
B. It lost 2 electrons
C. It gained 2 protons
D. It lost 2 neutrons
B. It lost 2 electrons
Two atoms of the same element have different mass numbers. What does this indicate?
A. Different number of protons
B. Different number of neutrons
C. Different number of electrons
D. Different elements
B. Different number of neutrons
Why do isotopes of the same element behave similarly in chemical reactions?
A. Same number of neutrons
B. Same number of protons and electrons
C. Same mass
D. Same energy levels only
B. Same number of protons and electrons
Which particle has no charge?
A. Proton
B. Electron
C. Neutron
D. Ion
C. Neutron
Element X has atomic number 20. One isotope has a mass number of 44. How many neutrons does it have?
A. 20
B. 24
C. 44
D. 64
B. 24
An ion has a charge of 2+ and contains 20 electrons. How many protons does it have?
A. 18
B. 20
C. 22
D. 24
C. 22
Which of the following best explains why isotopes have different atomic masses?
A. Different numbers of protons
B. Different numbers of electrons
C. Different numbers of neutrons
D. Different charges
C. Different numbers of neutrons
Which change would turn a neutral atom into a different element?
A. Gaining an electron
B. Losing a neutron
C. Gaining a proton
D. Losing an electron
C. Gaining a proton
The mass number of an atom is the sum of:
A. Protons and electrons
B. Electrons and neutrons
C. Protons and neutrons
D. Only protons
C. Protons and neutrons
If two atoms have the same number of protons but different numbers of electrons, they are:
A. Isotopes
B. Ions
C. Compounds
D. Neutrons
B. Ions
Which statement correctly compares two isotopes of the same element?
A. They have different numbers of protons and similar masses
B. They have the same number of neutrons but different electrons
C. They have the same number of protons but different masses
D. They have different charges but identical structures
C. They have the same number of protons but different masses
If an atom has an atomic number of 11 and a mass number of 23, how many neutrons does it have?
A. 11
B. 12
C. 23
D. 34
B. 12
What particle has a positive charge?
A. Electron
B. Neutron
C. Proton
D. Nucleus
C. Protons
Isotopes of the same element have different numbers of:
A. Protons
B. Electrons
C. Neutrons
D. Atomic numbers
C. Neutrons
An unknown element has 9 protons and 10 neutrons. What is its identity and mass number?
A. Fluorine, 19
B. Oxygen, 19
C. Fluorine, 9
D. Neon, 19
A. Fluorine, 19
Which particle is located outside the nucleus?
A. Proton
B. Neutron
C. Electron
D. Nucleus
C. Electron