It is challenging to determine which branch of chemistry has the highest scope as the scope and demand for different branches of chemistry can vary depending on several factors, such as technological advancements, societal needs, and economic trends. However, some branches of chemistry have been gaining significant attention and have a broad scope in recent years. Here are a few branches that are currently experiencing significant growth and offer substantial opportunities:

1. Biochemistry: With the advancement of biotechnology, personalized medicine, and the increasing understanding of biological processes at the molecular level, the field of biochemistry has seen tremendous growth. It plays a vital role in areas like drug discovery, genetic engineering, medical diagnostics, and understanding diseases.
2. Environmental Chemistry: As environmental concerns and sustainable practices gain importance, the field of environmental chemistry has a promising scope. Environmental chemists contribute to assessing and mitigating pollution, monitoring air and water quality, developing clean technologies, and addressing climate change issues.
3. Materials Chemistry: Materials chemistry is an interdisciplinary field that focuses on the synthesis, characterization, and manipulation of materials to enhance their properties and develop new materials for various applications. It is essential for advancements in areas like nanotechnology, energy storage, catalysis, electronics, and biomaterials.
4. Computational Chemistry: With the increasing computational power and availability of advanced modeling and simulation techniques, computational chemistry has become an indispensable tool for understanding complex chemical systems. It has applications in drug design, material discovery, reaction mechanisms, and the study of biomolecules.
5. Medicinal Chemistry: The demand for new and effective drugs to treat diseases and improve healthcare continues to grow. Medicinal chemistry plays a crucial role in designing and synthesizing novel drug compounds, optimizing their properties, and understanding their interactions with biological targets.
6. Nanotechnology: Nanotechnology involves manipulating and controlling matter at the nanoscale (1-100 nanometers). It has vast potential in various fields, including electronics, energy, medicine, materials science, and environmental remediation. Nanotechnology requires expertise from multiple branches of chemistry, physics, and engineering.

It’s important to note that the scope of these branches can change over time as new discoveries, technologies, and societal needs emerge. It is advisable to stay updated with current trends and developments in the field of chemistry to identify areas with promising opportunities.