<h2>Answer:</h2>
Low melting points and electrical conductivity in solids are not common properties of ionic solids.
<h3>Explanation:</h3>
In ionic compounds the electrons involved in the bonding are tightly packed under the influence of electrostatic force of attraction. So the movement of these electrons is very difficult.
In the melting point the bond breaking between the atoms is involved. Hence in case of ionic compound there is a high amount of energy needed to break the ionic bonds.
Electrical conductivity involves the free movement of electrons which is impossible in ionic solids.
So low melting points and electrical conductivity in solids are not common properties of ionic solids.
Answer:
The answer is
A. Switch
Explanation:
A switch is a device for making and breaking current in an electric circuit, it is mostly made of a non conducting material to prevent the user from being electrocuted, switches comes in range of types depending on the area of applications.
I will convert the unit of distance to SI unit for simplification.
1 mile = 1.6 km
Therefore, 0.245 mile = 0.245×1.6 = 0.392 km = 392 meters
Radio waves travels back after bouncing off from car.
Therefore, total distance traveled by radio waves = 2×392 = 784 meters.
Speed of radio waves = 3×10⁸ m/s
Therefore, time take by radar beam to <span> travel to a car and back = 784/3</span>×10⁸
=2.61×10⁻⁶sec