Sodium metal is soft with low melting point and low heat of fusion because metallic bond is week. Sodium metal has 1 valence electron per atom,
THE METALLIC BOND IS WEEK therefore it is not very strong so, SODIUM METAL IS SOFT..
OTHER metals are hard because they have strong metallic bonding,
These metals have high melting point because they have incomplete valence shell ,
As a result strong covalent bond between atom extends through out the crystals so,
THEY'RE HARD METALS.
(ANSWER FROM TAZEEM HAJRA)
well It Is hard because all rocks are hard
There are types of igneous rocks that are hard (eg granite) and others that are soft (eg volcanic ash). There are types of metamorphic rocks that are hard (eg gneiss) and others that are soft (eg marble). Thus "hardness" is not a characteristic that can be used to distinguish between the two.
No, rocks are typically hard and rigid due to their mineral composition and the way they are formed. Rocks can vary in hardness, with some being harder than others, but they are not squishy like softer materials.
Hardness in a rock has different meanings. Although sandstone, a sedimentary rock, may be composed of quartz grains (relatively hard on the Mohs scale of mineral hardness), it might be loosely cemented by calcite crystals which are not so hard, making it crushable by the squeeze of a hand. There are other well cemented sedimentary rock types that are very resistant to breaking, however. Certain limestones, breccias, conglomerates, and sandstones take great effort to break into smaller pieces. In general though, geologists will refer to sedimentary rock as soft rock, and igneous rock as hard rock. Igneous rock has an interconnected crystalline structure which makes it very resistant to fracture.
lake water is soft we have some by are cottage which we swim in the seaweed and smooth rocks help it to be soft i have to say interesting question
Hard matrix is supposed to be used for digging hard rocks and soft matrix for soft rocks. It's quite confusing to me
well It Is hard because all rocks are hard
Please describe what you mean by soft and rephrase the question.
compared to most rocks sandstone is rather soft and brittle, but the hardness of it varies greatly from rock to rock, some sandstone is so soft it can be crushed by stamping on it while other sandstone is so hard it can be used to build buildings
There are types of igneous rocks that are hard (eg granite) and others that are soft (eg volcanic ash). There are types of metamorphic rocks that are hard (eg gneiss) and others that are soft (eg marble). Thus "hardness" is not a characteristic that can be used to distinguish between the two.
well,the world may never know
The Characteristics are hard,soft,smooth,rough,large,small,etc.
Coal is typically considered to be a hard, black or brownish-black sedimentary rock formed from the remains of plants that lived millions of years ago. While it may not be as hard as some rocks, it is not classified as soft like clay or sand.
No, rocks are typically hard and rigid due to their mineral composition and the way they are formed. Rocks can vary in hardness, with some being harder than others, but they are not squishy like softer materials.
No. Some metals are hard, but some are soft.
Generally speaking, when a geologist talks of "soft rocks" and "hard rocks" what he or she means is "sedimentary rocks" or "igneous and metamorphic rocks". Limestone is a sedimentary rock, and compared to most other rocks, is relatively soft. lol Different limestones have different hardnesses. Most "marbles" are actually hard limestones, because they have not experienced the high pressures and temperatures required for metamorphism.
Rocks formed from thermal metamorphism are very hard. An example is hornfels. Just search thermal metamorphism and/or hornfels and you'll see some nice explanations on the web.