Study life

  A firewall is a software or hardware system designed to prevent unauthorized access to an individual computer or network of computers. They are used mostly as a first line of defense to protect your device or network from online threats such as hackers, viruses, Trojans, and worms. Every time you are connected to the Internet, your computer is exposed to all sorts of dangerous programs and malicious people that want to infiltrate your computer to steal your personal information, send spam emails to your inboxes, or use your computer to launch attacks on other computers. A good firewall system blocks attackers from trying to infiltrate your system and prevents your data and information from flowing out to the bad guys. Like a brick wall, a firewall acts as a barrier to protect your computer from online threats Fire walls have a similar function as the drawbridge and the portcullis grate in front of the entrance on a medieval castle-controlling who can go in and out. While a cast...

 The elements which have a tendency to form positive ions are known metals. The elements which have a tendency to form negative ions are known non-metals. The elements whose properties fall between those of metals and non-metals ore known metalloids. Metals Metals in their pure state, have metallic lustre. Metals are generally hard. • Some metals can be beaten into thin sheets. This property is called f malleability. ⚫ Metals are ductile, ie, thin wires can be drawn from metals. • Metals are good conductor of heat and electricity and have high melting points. Silver and copper are the best conductor of heat. Metals are solid but mercury is liquid at room temperature. . Their oxides are basic. With dil. HCl or H,SO,, they release H₂ gas. e.g., aluminium, copper, sodium, etc Non-metals . These can be solid, liquid or gas at room temperature. . These are neither malleable nor ductile. These are brittle. These do not conduct heat and electricity. C (graphite) is good conductor of elect...

 Force Force is a push or pull which can change the position of a body as required. It is a vector quantity following all the rules of vector. Forces are of two types 1. Balanced Forces If there are many forces acting on a body, but resultant of all of them is zero, then the forces are called balanced forces. 2. Unbalanced Forces If the resultant of all the forces is not zero, then the forces are called unbalanced forces. Newton's Law of Motion There are three laws of motion First Law "Everybody remains in its state of rest or state of motion, until an external force is applied on it." This law is also known as law of Inertia Inertia is a property by virtue of which, a body tries to retain its state. Inertia are of two types 1. Inertia of Rest If a body is in rest, then it will remain in rest until an external force is applied on it. 2. Inertia of Motion If a body is in motion, then it will remain in motion until an external force is applied on it. There are some examples...