A white precipitate close precipitate A suspension of particles in a liquid formed when a dissolved substance reacts to form an insoluble substance, eg in a precipitation reaction. This activity is in two parts – in the first, students make observations while carrying out the tests for various negative ions. To conserve power, the switch on the right side can be flipped to STANDBY; this turns the fan off and stops the measurement. Observation is key in this practical, as all the information needed will be seen in the reactions present. Universal 9V battery power supply and automatic shutdown functions are adopted to facilitate users' use and save energy.

To make the second part of the exercise more challenging, tests for positive ions could be introduced and students could be asked to identify both the positive and negative ions present in a solution. Before the lightning-prone season of each year, the lightning protection grounding, the collector shell, and the outer box grounding should be inspected and maintained. Ammonia solution is an irritant when concentrated, but not at the concentrations used by students in this activity. When wiring the 485 signal line, pay attention to the two wires A\B not to be reversed, and the addresses of multiple devices on the bus can not conflict.

RP 4: Carry out simple test-tube reactions to identify: cations (Group 2, NH₄⁺), anions (Group 7 [halide ions], OH⁻, CO₃²⁻, SO₄²⁻). INTIMATE TIPS】The measurement process, do not touch the metal piece to the back of the instrument, otherwise it would be inaccurate readings. It measures this number separately for positive and negative ions (+ and – ions are usually present simultaneously).

Using a high-precision negative oxygen ion measurement unit, long-term stability is good, and the drift is small. The installation needs to be stable, and the height between the center of the detector and the ground should be 1. APPLICATIONS】This Negative ion testing is designed for test high level concentration of negative or positive air ion. This is a stereo phone plug identical to the plug on small headphones in which the ground has been cut.Silver ions react with halide close halide A halide ion is an ion formed when a halogen atom (an atom from group 7) gains one electron. Ne ion test kits are commonly available, so they may be used to measure different types of negative ion test kits.