An object possessing an excess of 6.0 x 106 electrons has a net charge of...?

In which situation has the independent variable for the experiment been changed? check all that apply. changed from counting the number of duckweed at day 0 and day 14 to counting them every day changed from testing duckweed growth in beakers to testing duckweed growth in large outdoor tanks changed from testing the effect of ph on duckweed growth to testing the effect of light levels on duckweed growth changed from testing the effect of acid ph on duckweed growth to testing the effect of basic ph on duckweed growth

What is the measure of how much matter is in an object and that can be measured using a balance? a. height b. volume c. weight d. mass

The ph is the a. independent variable b. the dependent variable c. control group