Reports the results of testing 143 college freshmen on the meaning of density. Relates reasons for student inability to conceptualize density to the hierarchy of experiences which leads to the understanding of the density concept. (PR)

Describes a laboratory method of determining the formula for metal oxide, provides brief descriptions of two new courses at Kansas State Teachers College, and reports on meetings identifying critical needs in science education. (AL)

Describes effects of study time on acquisition retention processes in a general biology course designed for female freshmen and sophomores in high and low analytic-ability groups. Concluded the presence of positive reinforcement, expecially at high analytic level. (CC)

A laboratory demonstration is suggested for the formation of a-amylase enzyme in halved grains of barley. Data presented in the article provide some information of the pattern of a- and b-amylase activity during germination. (PS)

Describes a project-type undergraduate laboratory in electronics which utilizes integrated circuit operational amplifiers. Includes a brief account of ideal and nonideal operational amplifiers and a detailed description of the projects. (DF)