Which among the following is a element?

An element is a basic form of matter that cannot be broken down into simpler substances by chemical reactions [t4]. Graphite is a pure form of the element carbon [c3]. Specifically, graphite is one of the three main allotropes of carbon, alongside diamond and fullerenes [t4]. In graphite, each carbon atom is bonded to three others in a hexagonal planar array [c3]. In contrast, Alumina (aluminium oxide, Al2O3) and Silica (silicon dioxide, SiO2) are chemical compounds consisting of two different elements bonded together [c1, t1, t3]. Brass is not an element but a metal alloy, which is a mixture formed by the fusion of copper and zinc [t2, t6]. Therefore, among the given options, only graphite represents a pure elemental form.

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 4: Carbon and its Compounds > Allotropes of carbon > p. 61
2. [2] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 5: Environmental Pollution > Composition > p. 66
3. [3] https://www.elearning.rtb.gov.rw/mod/book/tool/print/index.php?id=1026&chapterid=3