Is there a waiting period...

...between clicking 'publish' and the instructable showing up on the site?

Topic by GanonsSpirit   |  last reply

who developed a periodic table?

 it is used to know the element that has atomic number.

Question by Waren-Neutron   |  last reply

Periodic Table of FAILURES

Hello everyone!! It has been a while since I have posted anything but I am back. So, I am currently a freshmen in high school, taking block science. I just started chemistry and was very excited having prior knowledge and love for it. The teacher give  us a paper with the Periodic Table of Elements on it. It was made by the Navy with a bunch of pictures of ships and what-not. So it seems legit. BUT, after closer inspection I discover this is as accurate as a un-modded Nerf gun. Many errors, ranging from spelling of elements to incorrect symbols and more.          So I issue a challenge. Since I have only knowledge of Chemistry I hope that here on Instructable's there are people who know it from the back of their head and can and will find the errors in this catastrophic table. I am posting a picture of it for you to investigate, if you need it to be clearer or anything else just ask. I am very curious to see what else on this is wrong. I have already marked and fixed a few errors with a pen, but I want to see if there are more!

Topic by ostomesto   |  last reply

Period Pad for dogs?

My Boston Terrier has her period. How do I make pads for her? Any suggestions?

Question by asladie   |  last reply

Periodic table of condiments

Nope, that isn't a typo. You've heard of the periodic table of elements? Well, check out this hilarious table of condiments that periodically go bad. From Condiment No. 1 (Mayonnaise, which the table says goes bad in 3 months) to Condiment No. 75 (Maraschino, which apparently never goes bad), you can look up just about any condiment you can name to see when you need to toss it out. Or at least when these people think it goes bad.Take it with a grain of salt (Condiment No. 2, it never goes bad!) though-it claims Lemon goes bad in 2 months. Stuff and nonsense. I've eaten 3 month old lemons that were perfectly good.Mendeleev would be so proud...

Topic by Lithium Rain   |  last reply

Periodic table closet

Hi, I'm 22 years old and I am in my master studies of chemistry. I thought would be a good time to start a collection of elements. I also want to display them properly. like in some sort of closet that you can hang to the wall. It is hard to type down where I am thinking of. The added image below is something like what I want (but in this picture they apparently forgot the Lanthanides and Actinides). How would you tackle to make something like that? I think wood is a good choice for material here (but please correct me if I'm wrong). I have a limited amount of experience of working with wood, but I figure the horizontal and vertical walls should slide into each other to make the grid. But I cannot figure out how to attach the grid to a sturdy back plate, or how to have smooth outside edges without wood sticking out to form the grid. I hope my explanations are some what clear. my explanation cortex seems not to be fully up to speed today. thank you in advance for you advice.

Topic by Jakwiebus   |  last reply

Does the Periodic Table Of LED's schematic work?

Im not going to elaborate on my project, I dont want anyone to steal it. Basically, its a LED Array in the shape of the periodic table. The small black circles are 4 way connections of all wires, if they intersect with no circle, they do not connect.

Question by PKTraceur   |  last reply

Info Resource: Periodic Table of Videos

Tables charting the chemical elements have been around since the 19th century - but this modern version has a short video about each one....Soon we'll be updating all the videos with new stories, better samples and bigger experiments.So once you've watched all 118 videos, make sure you come back soon and check on our progress. The sample video below should give you a taste of it :-) The LINK to the site

Topic by Goodhart   |  last reply

how to stop flow of electricity within a period of time? Answered

The concept of the circuit is, when electricity is applied to the circuit, it will stop the flow of electricity in 10 minutes. after 10 minutes the flow of electricity from the circuit to the load will be normal. for example my load is a refrigirator, when house electricity cuts off, as soon as the electricity is back, the refrigirator will not work within 10 minutes, after 10 minutes, it will be normal. any idea guys? any help would be very appreciated.

Question by sai00   |  last reply

Checking Theories

In this topic, place your theories of some chemistry experiments in the comments section, starting with this one. To start with, Fe + 2H2O --> FeO2 + 2H...Place iron fillings to fill 1/3 of a water bottle. Fill the rest with water, and place a balloon on top. Wait X days/weeks/months. The water reacts with the iron to extract the oxygen from the water, leaving only hydrogen, and rust in the products. In the reactants, the hydrogen was bonded to the oxygen.Will someone tell me if this works? The energy that bonds this is the potential energy in the water.

Topic by PKTraceur   |  last reply

has the IOT invitational application entry period ended yet?

I just entered the IOT invitational application essay for applying to get a kit and I was wondering if it made it thru to be checked

Question by jOker58   |  last reply

can a pop bottle capacitor store a charge for long periods of time?

I built a capacitor with tin foil salt water and a pop bottle and i was wondering if i could build one that would store a charge for a while, not just a fraction of a second.

Question by paperninja   |  last reply

When will the outdoor survival contest winners be announced? Answered

Just want to know. Why is there this waiting period after the judging? At first I thought that the winners are announced right after the judging ends, but I was wrong.

Question by pantherj12   |  last reply

does having a tuba on its bell for long periods of time flatten the bell? Answered

I was wondering because the 7 tuba players at our school are pretty lazy(i included) so after the class we usally just leave them upside down on the bells for the next class.

Question by tubanator-2.0   |  last reply

Extracting elements

Me and my friends are having a competition on who can fill their periodic tables with the purest element samples for the least amount of money. I was wondering if anyone had any suggestions for how to get less common elements such as gallium, tungsten, calcium, sodium, etc.

Question by pyrorower   |  last reply

Arduino resets periodically while being powered via an external power supply. Answered

I am using an 5V Arduino Mini ( While the Arduino is plugged into the 5v USB power coming from my computer it runs as expected (the lights flash in the right order and with the right timing, it accepts code etc.), but when it is powered through a regulated power supply it will turn on for a few seconds, then restart, run for a few more seconds, restart and repeat this indefinitely. I am programming it via an FTDI programmer (, and using two Polymer Lithium Ion Batteries ( wired in series to get it up to the necessary voltage. I have tried disabling auto reset via bridging 120 ohms equivalent resistance between RST and VCC and connecting a 10 micro-farad capacitor to RST and GND, but that did not solve the problem. I am fairly certain there are no problems with the code, because it runs perfectly when plugged into the computer, and I get the problem when running any code. If you need clarification or have any questions just ask. Thanks.

Question by GenAap   |  last reply

I want a power outlet that automatically shuts off after a period of time.

I want a device to plug my air compressor into that shuts off the power if the compressor runs for more than 20 minutes at a time. I leave my air compressor on and I am afraid that a leak will develop or a hose will burst leaving my compressor to run hours or days before I find it. I want it to sense when the air compressor starts pulling power and starts a timer. If the compressor is still running when the timer reaches either a preset time of around 20 minutes or an adjustable time, the power to the compressor is shut off until it is manually reset. My compressor is 110 volts and I live in the United States. Maybe such a thing exists but I haven't been able to find it. Thanks for your help, Kris

Topic by kingmanson   |  last reply

Arduino - Trigger only Section of sketch

Hi. My sketch is to run 3 different relays over a different periods. I am new to arduino, and what i Know up untill know I've learned from reading it up. Please help me how to use an input to trigger certain parts of the sketch(the different periods) Thanks!

Topic by Rookie89   |  last reply

Is there anything I can do to make a car starter run for longer periods of time? Answered

I was looking into using a modified car starter on a go cart and from what I've read they'll burn out if they're ran too long. Is there anything I could do to make them run longer without breaking? Or even why they burn out from continuous use?

Question by JasonYMN   |  last reply

555 working backwards?

Hey, so i wired up my 555, with a trigger button, and because i only had small resistors at the time, I used one to give a really quick period. however when i put in a brand new 800 KOhm resistor (that should have raised the period to 8 seconds) instead of lengthening the period it put a time limit on the trigger. so now i have an output that stays high for a faction of a second and then the chip can't be re-triggered for 8 seconds. i know people don't have an encyclopedic knowledge of 555, but does anyone more experienced have any ideas why this might have happened. thanks in advance.

Question by DrVonTrap   |  last reply

Dissolving material

Any material that dissolves in water after a particular period of time (eg:3000 litres) .. or any other way to achieve it..?

Topic by ursurya000007   |  last reply

Halloween challenges 2011

Looks like the judging period has been extended for the Halloween challenges.  Must be a tight race this year.

Topic by The Papier Boy   |  last reply

Slow Release compound in Water?

We are trying to fabricate an artificial bait for crab fishing and we are searching for a compound that we can mix the attractants in and that will dissolve slowly in water - thus releasing the bait-smell over a long period of time. Preferably over a period of 48 hours at the minimum at not too cold water temperatures. Does anyone have any ideas what type of compound this could be?

Question by perrap   |  last reply

Lego Party

Hi every body, I show you some period of time that I played Lego world, njoy

Topic by GameF   |  last reply

arduino uno programming?

I want a code in which as there is a change in resistance for sone millisecinds, arduino turns on led for a specific period of tie

Question by yhdesai 

My integrated stereo amplifier periodically stops working. Why does vacuuming it out fix it?

I've written an Instructable about this here:How to Fix Your Stereo Amplifier (Harman Kardon HK 620). It just stopped working, and again I vacuumed it out, fixing it. Others have shared similar experiences, but I don't know why it works.When the amp "stops working" everything but the amplifier appears to work: all the LEDs turn on, external devices plugged into the switched and non-switched 120 VAC ports energize, and the signal path out of the "tape 1 out" works.There's no visible dust inside the amp. I don't think it's a loose wire because "pretend" vacuuming (or shaking for that matter) has no effect. Do you have any ideas?

Question by ewilhelm   |  last reply

How would I add a timer to an alarm system to let it ring for a set period of time? Answered

Http:// Basically trying to add a timer to this alarm so it doesn't buzz until the battery is dead. I just need to know what parts I need and to wire this to that.

Question by Peace_Maker   |  last reply

Do I have a chance of winning a contest, if I'm not in the finalists, before the judging period ends?

Please answer my question to the best of your ability. I entered the solar contest with 2 entires and the judges choose 34 people to be finalists, but the judging does not end for a couple of more days. I'm not currently a finalist and was wondering if I have a chance in possibly in becoming one before the judging is over.

Topic by Navy Wolves   |  last reply

How do I design a circuit that will vary the intensity of a heating element over a 24hr period?

I am designing a 'heat box' for a college project, and basically I need to be able to control a heating element in such a way as to mimic the suns intensity on a typical day. so for example the heating element needs to come on at about 6 am at a low intensity, the intensity needs to slowly increase until say midday ( when it should peak) and then tail off until nightfall. any ideas?

Question by    |  last reply

Is there a permittivity and permeability table of the elements? Answered

I've found permittivity and permeability tables of the common metals, but none with all the elements. I know they measure them.

Question by Vorenus   |  last reply

Simple Lithium Cell Balancer?

Could your balance a lithium cell by simply hooking it up in parralel for a short period of time every once in a while?

Question by snowluck2345   |  last reply

How to Survive middle (or high, i dont know) school

That is it, the period from 13 year and ---year. i need a survival guide!

Topic by santy22   |  last reply

Hacking a program

Is there a way to remove the trial period from a program, say its gonna expire in 30 days, delete that piece of memory so it forgets and you have it forever? (photo courtesty of whatsisface)

Topic by Danny   |  last reply

Parts info please

Hi all: Does anyone know of a part that will swith  240v AC current on & off for short periods of time like a pulse effect ?. Thanks.

Topic by tezza1   |  last reply

Using bold automatically inserts spaces

I did a quick search and didn't see anything, so my apologies if this has already been reported: I am finding whenever I use bold to highlight words in my documents, an empty space is getting automatically inserted at the end of the word. For example, if I end this sentence with a word in bold and the turn off bold before using the period, there will end up being a space between the last word and the period which I did not put there and can not remove.

Topic by puzzlebox   |  last reply

Is there an way to display an clock with RetroPie?

Hi,I want to build an arcade.I want to use RetroPie.But is there an way to display the clock and weather after an period of time of inactivity? Sorry for bad english.

Question by Ferferite   |  last reply

Pdf problem

I'v e tried downloading the Mystic lord pdf file a couple of times but after a period of time I get a message to the effect that it's not able to repair the file. Is it my computer or is there a problem with that file ?

Topic by Floorman   |  last reply

Monthly Contests

I would like to see monthly or bi-monthly contests with no specific topic. Just a contest for the best instructable in that time period. It's a bummer to publish an instructable but not be eligible for any contests simply due to timing.

Topic by NightHawkInLight   |  last reply

about programming emf (Electromagnetic Field) detector

Excuse me, I would like to inquire about emf detector. I saw one of the projects in make emf with arduino, with LED bargraph. but here I replaced it with a small audio (8 Ohm), but why not come up with the perfect voice? This is my remake program   if(val >= 1){                    val = constrain(val, 1, senseLimit);     val = map(val, 1, senseLimit, 1, 1023);      total -= readings[index];                  readings[index] = val;           total += readings[index];                  index = (index + 1);                        if (index >= NUMREADINGS)                    index = 0;                               average = total / NUMREADINGS;              if (average > 50){                tone(10, 50, 100); delay(1000);     }     if (average > 150){              tone(10, 50, 200); delay(1000);    } if (average > 250){ tone(10,50,300); delay(1000);     } if (average > 350){ tone(10,50,400); delay(1000);     } if (average > 450){ tone(10,50,500); delay(1000);     } if (average > 550){ tone(10,50,600); delay(1000);     } if (average > 650){ tone(10,50,700); delay(1000);     } if (average > 750){ tone(100,50,800); delay(1000);     }         Serial.println(average);     delay(updateTime);   } } void tone(long duration, int freq) { duration *= 1000; int period = (1.0 / freq) * 1000000; long elapsed_time = 0; while (elapsed_time < duration) { digitalWrite(pinSpeaker,HIGH); delayMicroseconds(period / 2); digitalWrite(pinSpeaker, LOW); delayMicroseconds(period / 2); elapsed_time += (period);   } } please answer. Thank's.

Question by dzikriyana   |  last reply

Waveform Generator

Hi guys! So actually i wanted to make a circuit that can turn on and off an LED array at a particular rate (say 10 seconds time period). I want the LEDs to gradually brighten and dim. At first i thought i can implement it using a multi vibrator, but it it turning off and on too fast, since the output of the MV is a square wave. I want to design a simple circuit that can generate more slowly rising waveform (like sine or triangular) and can also drive a load of at least 100 mA and have a time period of 10 seconds or so. Any suggestions? 

Topic by charmquark   |  last reply

A little food and money set aside

Considering that we are overdue for a worldwide [ deflationary] period, it would be wise to have a little food and money set aside, "in case of a rainy day."FYI.

Topic by royalestel   |  last reply

Amazing Battery

This looks relatively easy to make;A stream of water is split into two streams and falls through two bottomless cans into two buckets. The falling water creates opposite electrical charges in the buckets, and high voltage arcs jump between them periodically.

Topic by radiorental   |  last reply

Payment and cancelation terms for PRO accounts

Subscribtion to get PRO is absolutely clear BUT: how to cancle this account and especially the donation/payment again? Is it limited to the periode of time payed in advance (e.g. one month) or will it be charged automatically till I cancle it?

Topic by drayson   |  last reply

Creaking under the Strain?

I've been getting periods of 503 errors (service unavailable) from Instructables recently. Are the servers creaking under the strain of all these weighty PRO members, or is the Instructables Robot hard at it mucking out the caches as he tweaks the privileges?

Topic by AndyGadget   |  last reply

Time constants of batteries ?

Hi,I'm trying to figure out the way solar battery charger work and I'm a bit confused about the following point.I read that for batteries you could consider the PWM voltage to be equivalent to DC. This I understand well for average voltage (obviously it's the same), but what about the dynamics ?If your PWM frequency is something like 100 kHz, that's a 10 µs period. Does the battery has time to follow and make big voltage and current peaks or does it just averages all that to more decent values ?One way to put it is : Are the battery time constants indeed much bigger than the PWM period ?Thanks for any idea on that topic !

Topic by Emmanuel2015   |  last reply