Learn Spanish (Spain): Él silencia el móvil en el trabajo.

In Spanish, locations related to institutions like work, school, or church usually require a definite article like el or la, whereas English leaves it out. Therefore, 'at work' is translated as en el trabajo.

Is 'silenciar' the standard way to say 'to mute' a device?

Yes! For phones, computers, and video calls, silenciar is the most common verb for 'to mute'. It literally means 'to silence', and it behaves as a completely regular -ar verb.

I previously learned 'celular' for cell phone. Is 'móvil' specifically used in Spain?

Exactly. In Spain, a mobile phone is called el móvil. In most of Latin America, you will hear el celular instead. They are perfectly interchangeable depending on the region you are in.

Could we drop the 'Él' at the start of the sentence?

Yes, you could just say Silencia el móvil en el trabajo. Spanish often drops subject pronouns. However, since silencia can mean 'he mutes', 'she mutes', or 'you (formal) mute', keeping Él clarifies exactly who is doing the action, or simply adds emphasis.