If only an element’s atomic number and weight are provided, what other atomic information can be determined for a neutral atom?
only the number of protons and electrons
only the number of protons and electrons
the number of protons, electrons and neutrons
the number of protons, electrons and neutrons
only the number of protons and neutrons
only the number of protons and neutrons
only the valence electrons
only the valence electrons
The answer is: only the number of protons and neutrons. The atomic number gives the number of protons, and the atomic weight gives a rough estimate of the number of neutrons. However, the presence or absence of electrons cannot be determined solely from the atomic number and weight. Valence electrons, which determine an element's chemical properties, cannot be determined from this information alone.
What quality differentiates hydrogen (H) from the other elements in group 1, the alkali metals?
It has more than one valence electron.
It has more than one valence electron.
It is found by itself in nature.
It is found by itself in nature.
It is a non-metal.
It is a non-metal.
It is not very reactive.
The answer is: It is found by itself in nature. Hydrogen is unique among the elements in group 1, the alkali metals, because it is found as a diatomic molecule (H2) rather than as a single atom. Alkali metals like lithium, sodium, and potassium are typically found in nature as single atoms.
On which atomic property proposed by Henry Moseley is the current periodic table of the elements based?
atomic number
atomic number
atomic weight
atomic weight
nucleus size
nucleus size
electric charge
The answer is: atomic number. The current periodic table of the elements is based on the atomic number, which was proposed by Henry Moseley. The atomic number represents the number of protons in the nucleus of an atom and determines the element's identity. This property is used to arrange the elements in the periodic table in increasing order of atomic number.
You plan to pass alpha particles through a field that contains a consistent type of particle. Which configuration will result in the largest deflection of alpha particles?
low-energy alpha particles passing through a field of low mass-number-particles
low-energy alpha particles passing through a field of low mass-number-particles
low-energy alpha particles passing through a field of high mass-number-particles
low-energy alpha particles passing through a field of high mass-number-particles
high-energy alpha particles passing through a field of low mass-number-particles
high-energy alpha particles passing through a field of low mass-number-particles
high-energy alpha particles passing through a field of high mass-number-particles
high-energy alpha particles passing through a field of high mass-number-particles
The answer is: low-energy alpha particles passing through a field of high mass-number particles.
Alpha particles are helium nuclei consisting of two protons and two neutrons. When alpha particles pass through a field of particles, they experience Coulombic interactions with the other particles due to their positive charge. The larger the mass of the particles in the field, the greater the chance of a larger deflection or scattering of the alpha particles. Low-energy alpha particles have less kinetic energy and are more likely to interact and be deflected by the higher mass particles in the field.
Which statement about metals and nonmetals is correct?
Most metals are a solid under normal conditions, and most nonmetals are a liquid.
Most metals are a solid under normal conditions, and most nonmetals are a liquid.
Metals tend to be poor conductors of electricity, while nonmetals are strong conductors of electricity.
Metals tend to be poor conductors of electricity, while nonmetals are strong conductors of electricity.
Metals and nonmetals can both be found in any column of the periodic table.
Metals and nonmetals can both be found in any column of the periodic table.
Metals can be hammered into thin sheets, and nonmetals are brittle.
The correct statement is: Metals can be hammered into thin sheets, and nonmetals are brittle.
Metals are generally malleable and ductile, meaning they can be hammered into thin sheets and drawn into wires. On the other hand, nonmetals are typically brittle, meaning they are easily broken or shattered when subjected to stress. This is one of the key characteristics that differentiate metals from nonmetals.
Based on properties of elements in the periodic table, which element is the best conductor of thermal energy?
argon (Ar)
argon (Ar)
vanadium (V)
vanadium (V)
germanium (Ge)
germanium (Ge)
polonium (Po)