Questions

First Jim and Jeanne walks across the bridge, it takes 2 minutes. 

Jim walks back with the torch light, which takes 1 minute. 

Then Louis and Anne walk on the bridge, which takes 10 minutes.

Jeanne comes back with the torch light, it takes 2 minutes.

Finally Jim and Jeanne walks across the bridge, which takes 2 minutes.

Total = 2 + 1 + 10 + 2 + 2 = 17 minutes

Ionic character depends on the electronegativity difference between the bonding elements. The greatest the elctronegativity diffference the greatest the ionic character.

Here in the given options, H-F has has the greatest ionic character. The electronegativity of Hydrogen is 2.1 and that of Fluorine is 4. Now the electronegativity difference is 4 - 2.1 = 1.9.

An ignition safety switch is a safety device can shut off the engine if the operator falls off the PWC or out of the powerboat, or is otherwise thrown from the proper operating position.

How it works:

It allows the engine of the vehicle to shut off or to be turned off immediately as it is to prevent further complications to happen as this is being used when an emergency is launched

Where it is used:

Most powerboats and PWCs come equipped by the manufacturer with an emergency engine cut-off switch.