**Author details**

Eko Hariyono<sup>1</sup> and Solaiman Liliasari<sup>2</sup> \*

\*Address all correspondence to: liliasari@upi.edu

1 Physics Department, Mathematics and Natural Science Faculty, State University of Surabaya, Surabaya, Indonesia

2 Science Education Program, School of Postgraduate Studies, Indonesia University of Education, Bandung, Indonesia
