Đề ôn thi Đề thi vào lớp 10 Trường Phổ thông Năng khiếu môn Tiếng Anh - Mã đề PTNK-17

A battery is a common device we use every day to power everything from remote controls to smartphones. But how does this small object store energy? The basic principle is quite simple: a battery doesn't store electrical energy directly. Instead, it holds chemical energy and converts it into electrical energy on demand. Inside a standard battery, there are several key components that work together to make this amazing process happen.

The main parts of a battery are its two terminals, one marked positive (+) and the other negative (-). Separating these terminals is a chemical substance called an electrolyte. When the terminals are connected to a device, like a lightbulb, a chemical (21) __________ takes place inside the battery. This reaction causes tiny particles called electrons to build up at the negative terminal, creating a difference in electrical potential between the two sides.

This difference in potential makes the electrons want to move from the negative terminal to the positive terminal. They travel through the external device in order to get there. This flow of electrons is exactly what we call an electrical current. The battery's internal chemical process is designed specifically to (22) __________ this movement of electrons. The flow creates a complete circuit, (23) __________ allows the battery to power the device.

However, this process cannot continue forever. The chemical reaction uses up the materials inside the battery. Once the chemicals in the electrolyte are depleted, they can no longer push electrons to the negative terminal. The flow of electrons stops, and we say the battery is 'dead'. This is why the power supply is not (24) __________; it has a limited lifespan determined by its chemical composition.

When you connect a battery to a phone or a toy, you are completing the circuit that allows the electrical current to flow and do its work. Every modern portable electronic device relies on this fundamental principle of converting stored chemical energy into useful electrical energy. Understanding this helps us appreciate the clever science packed into such a small and essential item.

The dream of becoming a famous online personality, whether on TikTok or YouTube, has captivated young people globally. The appeal is clear: millions of views, an outpouring of likes, and the chance to influence trends or launch a career. Success stories of those who "go viral" are everywhere, inspiring a generation to create. [I] While seeking online recognition can be exciting, is the constant chase for views and likes truly good for your well-being?

[II] This relentless demand for fresh, engaging content quickly turns creativity into a burden. Many young creators feel immense pressure to constantly outdo their last video, striving for relevance. The pursuit of viral content often becomes an obsession, leading to endless hours of brainstorming, filming, and editing. This constant pressure, coupled with comparison and fear of missing trends, frequently triggers significant stress, anxiety, and burnout. What began as fun transforms into a taxing competition for validation.

[III] In countries like Vietnam, where local TikTok stars achieve widespread fame, this phenomenon is particularly evident. Their success inspires many, sometimes leading individuals to engage in risky or dangerous "challenges" purely for views. News sites like VNExpress frequently report on these concerning trends, highlighting potential physical and emotional harm. The desire to "go viral" can overshadow common sense, pushing creators into situations compromising their safety or well-being for fleeting online attention.

[IV] Beyond physical risks, the emotional toll of chasing viral fame is profound. Your self-worth can become inextricably linked to your content's performance. A video with millions of views provides a massive dopamine hit, yet one with low engagement can lead to disappointment or feelings of inadequacy. This cycle of seeking external validation erodes genuine self-esteem, making the joy of creation dependent on fleeting metrics rather than personal satisfaction or artistic expression.

So, how can young people navigate this digital landscape responsibly? Remember, content creation should be for enjoyment and personal expression, not solely for fame. Prioritize your mental and physical well-being over digital metrics. Set boundaries, take breaks from endless scrolling, and appreciate your efforts regardless of view counts. While going viral is alluring, a healthy social media perspective ensures you enjoy its benefits without sacrificing your peace of mind.