The pitch of a theremin is controlled by creating a circuit between a variable oscillator and a reference oscillator, which should be available at specialty electronics stores as individual units. Each should be tuned to the same frequency, ideally in the middle of the low frequency radio range. The pitch-reference oscillator should work around 172kHz, used in conjunction with a 10k potentiometer. The signal this oscillator creates should be fed into the mixer with screened cable. The pitch-variable oscillator should also work around 172khz, and will be affected by the stray capacitance of the reference unit. Potentiometers need to be wired into the circuit to make the relationship of your hand movement to the change in pitch more linear. Without them, the instrument's pitch be almost impossible to control, changing wildly with only a microscopic movement of the hand. Using screened cable, wire the circuit of the pitch control components into the antenna when you're finished. When playing the theremin, your hand changes the capacitance of the antenna, which will change the frequency of the variable oscillator. Essentially, you're sending the signal into the antenna to be manipulated manually. This should also be in the low frequency radio range and carefully tuned, operating somewhere in the neighborhood of 441kHz. This signal will be influenced directly by the volume antenna, manipulating it by hand. A 10k trim potentiometer needs to be installed to enable the operator to tune the theremin appropriately. Send the output of this variable oscillator into a volume resonant circuit. The output will be a DC voltage that varies according to the output of the variable oscillator. Tuned correctly, the oscillator frequency will match the tuning of the volume-resonant circuit as the operator's hand approaches the antenna, causing the signal to cut off gradually. In other words, the closer the hand to the antenna, the quieter the sound. The purpose of the mixer is to compare the frequency of the variable oscillator with the reference frequency. The output will be an audio signal between 20Hz and 20kHz. Assembling the mixer is the simplest step in the process. Fed with two slightly different frequencies from the oscillators, the mixer will produce an output with a complex waveform, giving it the distinctive warble we associate with the sci-fi sound of the theremin. The output actually contains two distinct frequencies, which require the need of a low pass filter, that is two 0.0047uF capacitors and a 1k resistor, used to extract the output and boost it into a listenable range. Route the outputs of the mixer and the volume resonant circuit into a voltage-controlled amplifier. The voltage from the volume resonant circuit changes the amplitude of the audio signal from the mixer, helping to boost the sound and control the volume of the instrument.
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One-sentence summary -- Connect the pitch control. Connect the variable oscillator to the pitch antenna. Connect a variable oscillator to the volume antenna. Feed the output of each oscillator into a mixer. Route the signal from the mixer into an amplifier.

In naming compounds, Greek prefixes are used to indicate the number of atoms present for each element. Covalent compounds are written out as molecular formulas due to the fact that each compound is a distinct, separate molecule. Covalent compounds have the first element written out completely while the second element is named with the suffix "ide." For example, diphosphorus trisulfide has a chemical formula of P2S3. Below are the prefixes for 1-10: 1: Mono- 2: Di- 3: Tri- 4: Tetra- 5: Penta- 6: Hexa- 7: Hepta- 8: Octa- 9: Nona- 10: Deca- When a compound has been written out, you must identify the elements and know their chemical symbols. The first element written is "first name" of the compound. Use the periodic table to find the chemical symbol for the element. For example: Dinitrogen hexafluoride. The first element is nitrogen and the chemical symbol for nitrogen is N. To identify the number of atoms present for each element, you simply need to look at the prefix of the element. Memorizing the Greek prefixes will help you to be able to write chemical formulas quickly without looking anything up. For example: Dinitrogen has a the prefix "di-" which means 2; therefore, there are 2 atoms of nitrogen present. Write dinitrogen as N2. The second element is the "last name" of the compound and will follow the first element. For covalent compounds, the element name will have a suffix of "-ide" instead of the normal ending of the element. For example: Dinitrogen hexafluoride. The second element is fluorine. Simply replace the "ide" ending with the actual element name. The chemical symbol for fluorine is F. As you did with the first element, identify the number of atoms present in the second element by reading the prefix. Using this prefix, write the number of atoms as a subscript to the right of the chemical symbol. For example: Hexafluoride has a prefix of "hexa-" which means 6; therefore, there are 6 atoms of fluorine present. Write hexafluoride as F6. The final chemical formula for dinitrogen hexafluoride is N2F6. When first learning chemistry, there is a lot of memorization involved. It is kind of like learning a new language. The more examples you practice with, the easier it will be to decipher chemical formulas in the future and learn the language of chemistry. Sulfur dioxide: SO2 Carbon tetrabromide: CBr4 Diphosphorus pentoxide: P2O5
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One-sentence summary --
Memorize the prefixes for number of atoms. Write the chemical symbol for the first element. Add the number of atoms as a subscript. Write the chemical symbol for the second element. Add the number of atoms present as a subscript. Practice with some examples.