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2 years ago

What is rebar and why is it needed to make tall buildings?

Chemistry

1 answer:

AlexFokin [52]2 years ago

3 0

Answer:

rebar

is gridwork of steel rods

Explanation:

Reinforced concrete is one important component of skyscrapers. It consists of concrete (a mixture of water, cement powder, and aggregate consisting of gravel or sand) poured around a gridwork of steel rods (called rebar) that will strengthen the dried concrete against bending motion caused by the wind.

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The planets which lie beyond the asteroids are called the _____ planets.

scoray [572]

It is different everywhere you look but it's mainly asteroid belt

8 0

2 years ago

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An air mass usually forms in an area of _____. low pressure because it's stable low pressure because it's unstable high pressure

horsena [70]

Answer: high pressure because it's stable

Explanation:

Air mass is volume of air which has stable temperature, humidity and pressure horizontally. Over time, each air mass acquires properties of the region by residing over same part of a surface.

Areas of low pressure and high pressure occur where there is warm air and cold air respectively. An air mass usually forms over an area of high pressure. Warm air rises up and cold air takes its place. Warm air has low density and low pressure where as cold air has high density and pressure and therefore, sinks to the bottom. This is a stable condition. The movement of air mass is responsible for maintenance of temperature conditions on Earth.

6 0

3 years ago

Which is a pure substance? soda gasoline salt water carbon dioxide

hram777 [196]

Answer: Carbon dioxide is a pure substance.

Explanation: A pure substance is defined when a substance has a single type of molecule. If more than 1 type of molecule is present in a substance, then it is considered as a mixture.

Soda is basically a mixture of water and carbon dioxide. More than 1 type of molecule is present.

Gasoline is a mixture of may gases. More than 1 type of molecule is present.

Salt water contains salt and water molecules, hence it is considered as a mixture.

Carbon dioxide has only 1 type of molecule which is $CO_2$ molecules. Hence, it is a pure substance.

8 0

2 years ago

Read 2 more answers

At constant pressure, which of these systems do work on the surroundings? A ( s ) + B ( s ) ⟶ C ( g ) A(s)+B(s)⟶C(g) 2 A ( g ) +

Tju [1.3M]

Correct question:

At constant pressure, which of these systems do work on the surroundings?

(a) A ( s ) + B ( s ) ⟶ C ( g )

(b) 2 A ( g ) + 2 B ( g ) ⟶ 5 C ( g )

(d) 2 A ( g ) + 2 B ( g ) ⟶ 3 C ( g )

Answer:

(a) A ( s ) + B ( s ) ⟶ C ( g )

(b) 2 A ( g ) + 2 B ( g ) ⟶ 5 C ( g )

Explanation:

Work done by a system on the surroundings at a constant pressure is given as;

W = -PΔV

Where;

ΔV is gas expansion, that is final volume of the gas minus initial volume of the gas must be greater than zero.

Part (a)

A ( s ) + B ( s ) ⟶ C ( g )

ΔV = 1 - (0) = 1 (expansion)

Part (b)

2 A ( g ) + 2 B ( g ) ⟶ 5 C ( g )

ΔV = 5 - ( 2+ 2) = 1 (expansion)

Part (c)

A ( g ) + B ( g ) ⟶ C ( g )

ΔV = 1 - ( 1 + 1) = -1 (compression)

Part (d)

2 A ( g ) + 2 B ( g ) ⟶ 3 C ( g )

ΔV = 3 - ( 4) = -1 (compression)

Thus, systems where there is gas expansion are in part (a) and part (b). The correct answers are:

(a) A ( s ) + B ( s ) ⟶ C ( g )

(b) 2 A ( g ) + 2 B ( g ) ⟶ 5 C ( g )

4 0

2 years ago

Be able to identify the correct elements using clues such as numbers of protons,locations (family/period), number of neutrons, n

Brilliant_brown [7]

an element's name, chemical symbol, atomic number, atomic mass.

IDK what you are even asking for

6 0

3 years ago