I already have a NE555 connected properly in my breadboard in astable configuration. I want to generate a pulse with a period equal to 0.1 seconds. What values of resistances should I use given that I have a 100nF capacitor.

 

I already have a NE555 connected properly in my breadboard in astable configuration. I want to generate a pulse with a period equal to 0.1 seconds. What values of resistances should I use given that I have a 100nF capacitor.

Check this out......

NE555

 

What values of resistances should I use given that I have a 100nF capacitor.

Since you've selected a capacitor value, calculating period is straightforward. Just remember to consider component tolerance.
\( \small t = 1.1RC => R = \frac{t}{1.1C} \)

Or you can use this graph from the datasheet for quick approximations:


There's a typo. There is no RB.

EDIT: cleaned up tex block.

 

Try 910K ohms....

 

First you said you built an NE555 astable that is a continuously running oscillator. Then you said you want to generate "a pulse" which is a triggered monostable NE555 circuit. The monostable circuit is shown above.
What will trigger your monostable? It must be a momentary pulse to 0V to pin 2.