Air column: space within the percussion instrument that determines the pitch. Percussion: sounds produced by striking the instrument with a mallet or stick, or striking one instrument against another. 2. Review the process of forming a hypothesis and making a prediction.
Dig short, shallow rows. The rows should be no more than 1/2 inch (1.5 centimeters) deep and spaced 4 inches (10 centimeters) to 6 inches (15 centimeters) apart. 3. Drop the seeds into the rows. Space the seeds approximately 1 inch (25 millimeters) apart in order to allow the onions enough room to grow and mature.
1 If you are growing sweet onions from seeds, plant each seed 3/8 of an inch (1 cm) deep and 1/2 inch (1.3 cm) apart. 2  When you plant rows, make sure they are 15 inches (38 cm) apart. 3  Once they become seedlings, you will want to thin your onions until they are 3 inches (7.6 cm) apart. Rows should remain separated by 15 inches (38 cm). 2  If you are planting sweet onions from sets, plant them 3 inches (7.6 cm) apart, and rows at 15 inches (38 cm) apart. 3  Plant them shallowly, with the roots into the ground, and the bulb only about 1/4 inch (0.6 cm) into the ground.