Which substance below would be classified as a compound?
He
N2
NH3
O2
A student describes a sample with the chemical formula 2 NH3. Which statement below best describes this substance?
There are three molecules; each molecule is made of 2 nitrogen atoms and 1 hydrogen atom.
There are two molecules; each molecule is made of 3 nitrogen atoms and 3 hydrogen atoms.
There are two molecules; each molecule is made of 1 nitrogen atom and 3 hydrogen atoms.
There are 2 molecules; each molecule is made of 3 NH atoms
A chemist isolated a sample of water, which is represented in the diagram shown to the right. Based on the diagram shown, in what state is the water and why?
The water is in the gaseous state because the molecules are close together and have strong attractive forces between them.
The water is in the solid state because the molecules are close together and have strong attractive forces between them.
The water is in the solid state because the molecules are far apart and have weak attractive forces between them.
The water is in the gaseous state because the molecules are far apart and have weak attractive forces between them.
Which of the following statements is true about fluorine?
Each fluorine atom contains 9 protons, 9 neutrons, and 9 electrons.
Each fluorine atom contains 9 protons, 19 neutrons, and 9 electrons.
Each fluorine atom contains 9 protons, 10 neutrons, and 10 electrons.
Each fluorine atom contains 9 protons, 10 neutrons, and 9 electrons.
Which of the following is NOT true about electrons?
They are found in the nucleus of an atom
They are repelled by other electrons.
They are attracted to the protons of the nucleus.
They are found in the orbitals of electron shells.
An unknown element has 2 energy shells and 6 valence electrons. What is the element?
Helium
Carbon
Oxygen
Barium
Why are Helium, Neon, and Xenon present in different periods of the periodic table?
All three elements have the same number of valence electrons.
All three elements have the same reactivity.
All three elements have a different number of valence electrons.
All three elements have a different number of energy shells.
Which of the following atoms is most likely to be shiny, malleable, ductile, and conductive?
Cesium
Argon
Carbon
Iodine
Which of the following elements will have metallic and non-metallic properties?
Carbon
Krypton
Magnesium
Germanium
Which statement below best explains why the atomic radius of lithium is larger than the atomic radius of hydrogen?
Lithium has more protons, so it attracts its valence electrons closer to the nucleus.
Lithium has more energy levels, so its valence electrons are further away from the nucleus.
Hydrogen has fewer protons, so it attracts its valence electrons closer to the nucleus.
Hydrogen has fewer energy levels, so its valence electrons are further away from the nucleus.
Which of the following correctly lists the elements from lowest to highest ionization energy? Neon, Fluorine, Nitrogen, Silicon
Nitrogen, Fluorine, Neon, Silicon
Silicon, Neon, Fluorine, Nitrogen
Silicon, Nitrogen, Fluorine, Neon
Neon, Fluorine, Nitrogen, Silicon
Which of the following compounds below contains ionic bonding?