Match the words with their definitions

surface	to show something that was previously hidden
length	if a substance contains something, that thing is part of it
strength	the outside or top layer of something
bond	the natural ability of a person, animal, or plant to stop diseases or difficult conditions from harming them
to reveal	to talk or write about something or someone, usually quickly and without saying very much or giving details
to contain	the measurement of how long something is from one end to the other
resistance	the size or level of something, or the amount that something is happening
to mention	how strong an object or structure is, especially its ability to last for a long time without breaking
scale	the chemical force that holds atoms together in a molecule

Text А. Structure

As mentioned above, structure is one of the most important components of the field of materials science. Materials science examines the structure of materials from the atomic scale, all the way up to the macro scale. Characterization is the way materials scientists examine the structure of a material. This involves methods such as diffraction with X-rays, electrons, or neutrons, and various forms of spectroscopy and chemical analysis such as Raman spectroscopy, energy-dispersive spectroscopy (EDS), chromatography, thermal analysis, electron microscope analysis, etc.

Structure is studied at various levels. Atomic structure deals with the atoms of the materials, and how they are arranged to give molecules, crystals, etc. Much of the electrical, magnetic and chemical properties of materials arise from this level of structure. The length scales involved are in angstroms. The way in which the atoms and molecules are bonded and arranged is fundamental to studying the properties and behavior of any material. Nanostructure deals with objects and structures that are in the 1—100 nm range. In many materials, atoms or molecules agglomerate together to form objects at the nanoscale. This causes many interesting electrical, magnetic, optical, and mechanical properties. Microstructure is defined as the structure of a prepared surface or thin foil of material as revealed by a microscope above 25× magnification. It deals with objects from 100 nm to a few cm. The microstructure of a material (which can be broadly classified into metallic, polymeric, ceramic and composite) can strongly influence physical properties such as strength, toughness, ductility, hardness, corrosion resistance, high/low temperature behavior, wear resistance, and so on. Most of the traditional materials (such as metals and ceramics) are microstructured.

The manufacture of a perfect crystal of a material is physically impossible. For example, a crystalline material will contain defects such as precipitates, grain boundaries (Hall–Petch relationship), interstitial atoms, vacancies or substitutional atoms. The microstructure of materials reveals these defects, so that they can be studied. Macro structure is the appearance of a material in the scale millimeters to meters—it is the structure of the material as seen with the naked eye.

Find in the text the verbs in the Passive Voice and state the tenses they are used in.

6. Join the halves of the sentences in the columns:

Atomic structure deals with the atoms of the materials, and how they	agglomerate together to form objects at the nanoscale.
In many materials, atoms or molecules	can strongly influence physical properties
Microstructure is defined as the structure of a prepared surface or thin foil of material as	are arranged to give molecules, crystals, etc.
The microstructure of a material	revealed by a microscope above 25× magnification.

7. Answer the questions:

What methods are used to study the structure of materials?

At what levels is structure of materials studied?

From which level do most properties of materials arise?

What parameter is fundamental in studying the behaviour of materials?

What is the difference between atomic, nano, micro and microstructure?

Is it possible to manufacture a perfect crystal? Why?

8. Read the text and answer the question: