commercially available cold packs are simple in design: a pouch with water on one side, isolated by a barrier from a specific salt on the other side. when the barrier is broken, the salt and water mix and the solution turns cold. select which of the statements is true about the reaction occurring in cold packs.

We the people of the united states, in order to form a more perfect union, establish justice, insure domestic tranquility, provide for the common defence, promote the general welfare, and secure the blessings of liberty to ourselves and our posterity, do ordain and establish this constitution for the united states of america. according to the preamble which action represents an appropriate role for government

Assessment includes a. interviews, recorded conversations, videos, frequency counts, and time samples. b. formal standardized tests and developmental screening tools. c. various types of documented observations, documentation of child work, checklists, rating scales, and standardized tests. d. anecdotal notes, narratives or daily records, daily health checks, and teacher observation checklists.

Which of the following always exist between two objects having mass ● elastic force ● contact force ●gravitational force ●magnetic force