Blockchain technology has recently gained significant traction to support collaborative processes due to its ability to enable decentralization in environments that do not require a central authority. While there are numerous model-to-code approaches to facilitate the deployment and execution of processes on the blockchain, few have addressed the critical aspect of explicit modeling and designing blockchain-enabled processes. This paper introduces BPMN4BC, an extended set of notations designed to represent blockchain properties in process diagrams. These notations help distinguish on-chain from off-chain logic, preventing their overlap and accurately representing blockchain transactions. BPMN4BC enables business users and domain experts to capture blockchain-specific properties within their collaborative process models explicitly. We also introduce the BPMN4BC compiler that generates and deploys the corresponding Solidity code. To assess the consequences of different modeling choices, we compare the execution cost associated with two alternative deployment strategies, thereby demonstrating how modeling decisions influence blockchain properties such as gas usage.