Answer:
Explanation:
Galaxies are moving closer
There are 3 states of matter. Solid, Liquid, Gas. An example of each would be ice, water, steam,
Answer:
Approximately 
, assuming that 
Explanation:
The weight of the elevator is:
.
Since the speed of the elevator is constant, the acceleration of this elevator would be 
.
By Newton's Second Law of Motion, the net force on the elevator (proportional to acceleration) would also be 
. All external forces on the elevator need to be balanced in every direction.
The only two vertical forces on the elevator are:
- the weight of the elevator (downward gravitational pull from the earth,) and
- the upward pull from the motor.
These two forces need to balance one another. Since the weight of the elevator is approximately 
, the upward pull of the motor would be 
. in magnitude.
The direction of this upward pull is the same as the direction of the motion of this elevator. Thus, the work that the motor did on the elevator would be positive:
.
Since the velocity of the elevator is constant, instantaneous power output of the motor would be equal to the average power of the motor:
.
Answer;
D. The group number is equal to the number of valence electrons.
Explanation;
-The valence electrons are the electrons in the outer shell of an atom. The valence electrons are the ones involved in forming bonds to adjacent atoms. Therefore, the number of valence electrons is important for determining the number of bonds an atom will form, the number of unpaired electrons, and an atom’s formal charge.
-For neutral atoms, the number of valence electrons is equal to the atom’s main group number.
Number of valence electrons = main group number (neutral atoms)
-The main group number for an element can be found from its column on the periodic table. For example, carbon is in group 4 and has 4 valence electrons. Oxygen is in group 6 and has 6 valence electrons.
