Which statement describes the relative masses of two different particles?

1.a neutron has less mass than a positron.
2.a beta particle has less mass than a neutron.
3.an alpha particle has less mass than a positron.
4.an alpha particle has less mass than a beta particle.

What type of reaction is shown below? check all that apply. 2h2o2 → 2h2o + o2 synthesis decomposition combustion

Avariable that is not being directly tested during an experiment should be changed varied experimented controlled

15. which of the following is not human-caused groundwater pollution? a. water in an aquifer dissolves elements such as arsenic and mercury from surrounding rock. b. water in an aquifer is contaminated by leachate that seeps into the ground from a landfill. c. water in an aquifer becomes polluted with chemicals used in hydraulic fracturing, or fracking. d. water in an aquifer absorbs harmful bacteria from the drainage field of a septic tank.