Lobsters, like snails and spiders, have blue blood due to the presence of hemocyanin, which contains copper. In contrast, vertebrates and many other animals have red blood from iron-rich hemoglobin.

Graphite is a covalent-network type of crystalline solid.

There are two main categories of solids.

1. Crystalline solids and

2. Amorphous solids.

Crystalline solids are those in which the atoms, ions, or molecules that make up the solid exist in a regular, well-defined arrangement.

There are four types of crystalline solids :

Ionic solids :— Made up of positive and negative ions and held together by electrostatic attractions. They’re characterized by very high melting points and brittleness and are poor conductors in the solid state. An example of an ionic solid is table salt, NaCl.

Molecular solids :— Made up of atoms or molecules held together by London dispersion forces, dipole-dipole forces, or hydrogen bonds. Characterized by low melting points and flexibility and are poor conductors. An example of a molecular solid is sucrose.

Covalent-network (also called atomic) solids :— Made up of atoms connected by covalent bonds; the intermolecular forces are covalent bonds as well. Characterized as being very hard with very high melting points and being poor conductors. Examples of this type of solid are diamond and graphite, and the fullerenes. As you can see below, graphite has only 2-D hexagonal structure and therefore is not hard like diamond. The sheets of graphite are held together by only weak London forces!

Metallic solids :— Made up of metal atoms that are held together by metallic bonds. Characterized by high melting points, can range from soft and malleable to very hard, and are good conductors of electricity.

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As parabola is a locus of a point, which moves so that its distance from focus and directrix is always equal.

The latus rectum of a conic section is the chord (line segment) that passes through the focus, is perpendicular to the major axis and has both endpoints on the curve. The length of the latus rectum is determined differently for each conic.

The length of a parabola's latus rectum is 4p, where p is the distance from the focus to the vertex.

From the given data,

18 snakes can eat 18 bananas in 18 hrs.

=> 1 snake can eat 1 banana in 18 hrs

=> 79 snakes can eat 79 bananas in 18 hrs.

Hence, 18 hrs.

Euclid of Alexandria was a Greek mathematician, often referred to as the Father of Geometry.

In India, Fiscal Policy is formulated by the Ministry of Finance.

Fiscal policy is playing an important role on the economic and social front of a country. Traditionally, fiscal policy is concerned with the determination of state income and expenditure policy. But with the passage of time, the importance of fiscal policy has been increasing continuously for attaining rapid economic growth.

An effective fiscal policy is composed of policy decisions relating to the entire financial structure of the government including tax revenue, public expenditures, loans, transfers, debt management, budgetary deficit, etc.

During convection, cool and dense air falls through the warmer and less dense air. The warm air having less mass is being displaced by the cooler which is much heavy. Convection always involves the air rising through the atmosphere.