Atomic Nature
In an electrically neutral atom, which relationship is always true?
A- Protons outnumber electrons
B- Protons equal the number of electrons
C- Neutrons equal the number of electrons
D- Atomic Mass equals atomic number
B- Protons equal the number of electrons
A submerged object experiences an upward buoyant force because:
A.Liquid density decreases with depth
B.Pressure against the bottom exceeds pressure on top
C.Atmospheric pressure pushes downward
D.Liquid molecules expand underneath
B.Pressure against the bottom exceeds pressure on top
Atmospheric pressure at sea level is primarily caused by:
A.Solar radiation heating
B.The weight of the overlying air column
C.Earth's daily rotation
D.Magnetic field containment
B.The weight of the overlying air column
A person lies on a bed of 1,000 sharp nails unharmed. This demonstrates:
Pressure = Force / Area (large area reduces pressure)
The chemical identity of an element is uniquely determined by its,
A- number of valence electrons
B- number of neutrons in nucleus
C- Number of protons in nucleus
D- Total atomic mass.
C- Number of protons in nucleus
Hooke's Law states that the stretch of an elastic body is directly proportional to:
A.Applied force
B.Square root of length
C.Total mass squared
D.Elastic limit threshold
A.Applied force
An object will sink in a fluid if its average density is:
A.Greater than the fluid's density
B.Less than the fluid's density
C.Equal to the fluid's density
D.Equal to atmospheric density
A.Greater than the fluid's density
Why is mercury preferred over water in traditional barometers?
A.Mercury is less dense than water
B.Its high density allows a convenient column height (76 cm)
C.Mercury cannot freeze
D.Mercury molecules don't exert pressure
B.Its high density allows a convenient column height (76 cm)
A submarine sinks deeper into the ocean by
Flooding ballast tanks with water to increase weight
Which constituent accounts for nearly all of an atom's physical mass?
A. Orbiting electron cloud
B- Positrons and photons
C.The atomic nucleus (protons & neutrons)
D.Electrostatic energy fields
C. The atomic nucleus (protons & neutrons)
A 2 N load stretches a spring 3 cm. Within elastic limits, a 6 N load stretches it:
A.3 cm
B.6 cm
C.9 cm
D.12 cm
C.9 cm
An iron ship floats because its hollowed hull:
A.Decreases the density of water
B.Displaces water weighing more than the ship
C.Lowers average density below water's density
D.Repels liquid magnetically
C.Lowers average density below water's density
An unconstrained helium balloon released into the air will continue to rise until:
A.It reaches the vacuum of space
B.Balloon density equals surrounding air density
C.Atmospheric pressure drops to zero
D.The gas inside cools to absolute zero
B.Balloon density equals surrounding air density
Why does a sharp chef's knife cut food much more easily than a dull one
A smaller contact area concentrates applied force into high pressure
Atoms of the same element that have different masses are termed:
A.Isotopes
B.Allotropes
C.Ions
D.Isomers
A.Isotopes
Surface tension in water droplets is caused primarily
by:
A.Gravitational collapse
B.Atmospheric downward compression
C.Molecular cohesive forces pulling inward
D.Viscous friction between fluid layers
C.Molecular cohesive forces pulling inward
Bernoulli's principle states that where the speed of a flowing fluid increases
A.Internal fluid pressure decreases
B.Internal fluid pressure increases
C.Fluid density triples instantly
D.Fluid temperature reaches absolute zero
A.Internal fluid pressure decreases
If an ice cube floating in a full glass of water melts completely, the water level
Remains exactly unchanged
Brownian motion is direct macroscopic evidence that:
A.Atoms are stationary at room temp
B.Fluid particles are in perpetual random motion
C.Light exerts radiation pressure
D.Gravity pulls down atoms
B.Fluid particles are in perpetual random motion
Scaling law: When a cube's linear dimensions double, its surface area multiplies by:
A.2
B.4
C.8
D.16
B.4
A 10 N rock submerged in water weighs 7 N on a scale. The buoyant force is:
A.17 N
B.10 N
C.3 N
D.7 N
C.3 N
Unlike standard neutral gases, plasmas readily:
A.Resist all magnetic fields
B.Conduct electric currents and respond to magnetism
C.Have definite shape and volume
D.Form rigid crystalline lattices
B.Conduct electric currents and respond to magnetism
An inflated balloon placed inside a freezer shrinks because
Lower temperature reduces kinetic energy and gas pressure.