What is the difference between the chemical bonds formed in molecules of N2 and the chemical bonds formed in crystals of Mgo?
A. MgO is a covalent substance, and N2 is an ionic substance.
B. Both N2 and MgO are covalent substances, but the bonding
electrons in MgO are shared more equally between atoms than
they are in N2
C. Both N2 and MgO are covalent substances, but the bonding
electrons in N2 are shared more equally between atoms than they
are in Mgo.
D. Mgo is an ionic substance, and N2 is a covalent substance.

Air is held within a frictionless piston-cylinder container, which is oriented vertically. the mass of the piston is 0.45 kg and the cross-sectional area is 0.0030 m2. initially (state 1) the pressure of the gas is sufficient to support the weight of the piston as well as the force exerted by the atmospheric pressure ( 101.32 kpa). the volume occupied by the air within the cylinder in state 1 is 1.00 liter. one end of a spring (with spring constant k = 1000 n/m) is attached to the top of the piston, while the other end of the spring is attached to a stage that can move vertically. initially the spring is undeflected and therefore exerts no force. then the stage is then moved quasistatically downward a distance of 10.0 cm, at which point the system reaches state 2. the piston-cylinder is not insulated; rather it remains in diathermal contact with the surroundings, which are at a constant temperature of 300 k. what is the change of pressure within the container?

The air that we breath is made mostly of which gaseous molecule

Aball thrown by ginger is moving upward through the air. diagram a shows a box with a downward arrow. diagram b shows a box with an upward arrow. diagram c shows a box with a downward and upward arrow equal in size. diagram d shows a box with a downward and upward arrow with the downward arrow larger in size. which force diagram represents the forces on the ball? you may neglect the effects of air resistance.