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3 years ago

Why are teeth not minerals?

2 answers:

7 0

Because your Teeth are composed of calcium, phosphorus, and other minerals. ... But bones are still not as strong as teeth. The hardest part of the human body ,teeth mostly consist of a calcified tissue called dentine. The tooth's dentine tissue is covered in enamel, that hard, shiny layer that you brush.

devlian [24]3 years ago

6 0

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Please help me very easy will biraly and 5 star and thanks

cestrela7 [59]

ITS 40 GRAMS I THINK

7 0

2 years ago

Read 2 more answers

_____Mg + ____Fe2O3 → _____Fe + ____MgO

german

Answer:

3Mg + Fe₂O₃ → 2 Fe + 3MgO

Explanation:

Chemical equation;

Mg + Fe₂O₃ → Fe + MgO

Balanced Chemical equation;

3Mg + Fe₂O₃ → 2Fe + 3MgO

This is the balanced equation. There are three magnesium, two iron and three oxygen atoms are on both side of equation thus it follow the law of conservation of mass.

Law of conservation of mass:

According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.

This law was given by french chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.

7 0

3 years ago

What is the difference between atomic mass, relative atomic mass and average atomic mass

vesna_86 [32]

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Difference between Atomic mass, relative atomic mass and average atomic mass :-

<h3>Atomic Mass :-</h3>

Atomic mass is the mass of neutrons and protons present in the nucleus of an atom .
It is always calculated for a single element and having direct value
For isotopes also, the atomic mass is calculated separately . Example :- Carbon 12 , carbon 13 and carbon 14 have different atomic mass. 
The SI unit of Atomic mass is " u" and "amu"

<h3>Relative Atomic mass :-</h3>

Relative atomic mass is mean mass of the atoms of an element which is compared to the 1/12th mass of carbon - 12 .
Carbon - 12 is taken as a relative when we calculate the relative atomic mass of any element
For calculating relative atomic mass, we need to know the masses, percentage and abundance of all types of elements
Relative atomic mass is a dimension less quantity

<h3>Average Atomic Mass :-</h3>

Average atomic mass is the average mass of an atoms of a particular element by considering it's isotopes
While we calculate average atomic mass is a standardized number. Whereas, Average atomic mass sometimes varies geologically .
It also includes percentage, abundance and masses of given element .
In average atomic mass, We do not compare mean value with the 1/12 mass of carbon - 12
The unit of Average atomic mass is "Amu" or " u " .

5 0

2 years ago

Explain what happens to the light ray when above and below the line are both water

IceJOKER [234]

<>"Refraction is the bending of the path of a light wave as it passes from one material into another material. The refraction occurs at the boundary and is caused by a change in the speed of the light wave upon crossing the boundary. The tendency of a ray of light to bend one direction or another is dependent upon whether the light wave speeds up or slows down upon crossing the boundary. The speed of a light wave is dependent upon the optical density of the material through which it moves. For this reason, the direction that the path of a light wave bends depends on whether the light wave is traveling from a more dense (slow) medium to a less dense (fast) medium or from a less dense medium to a more dense medium. In this part of Lesson 1, we will investigate this topic of the direction of bending of a light wave.

Predicting the Direction of Bending

Recall the Marching Soldiers analogy discussed earlier in this lesson. The analogy served as a model for understanding the boundary behavior of light waves. As discussed, the analogy is often illustrated in a Physics classroom by a student demonstration. In the demonstration, a line of students (representing a light wave) marches towards a masking tape (representing the boundary) and slows down upon crossing the boundary (representative of entering a new medium). The direction of the line of students changes upon crossing the boundary. The diagram below depicts this change in direction for a line of students who slow down upon crossing the boundary.

On the diagram, the direction of the students is represented by two arrows known as rays. The direction of the students as they approach the boundary is represented by an incident ray (drawn in blue). And the direction of the students after they cross the boundary is represented by a refracted ray (drawn in red). Since the students change direction (i.e., refract), the incident ray and the refracted ray do not point in the same direction. Also, note that a perpendicular line is drawn to the boundary at the point where the incident ray strikes the boundary (i.e., masking tape). A line drawn perpendicular to the boundary at the point of incidence is known as a normal line. Observe that the refracted ray lies closer to the normal line than the incident ray does. In such an instance as this, we would say that the path of the students has bent towards the normal. We can extend this analogy to light and conclude that:

Light Traveling from a Fast to a Slow Medium

If a ray of light passes across the boundary from a material in which it travels fast into a material in which travels slower, then the light ray will bend towards the normal line.

The above principle applies to light passing from a material in which it travels fast across a boundary and into a material in which it travels slowly. But what if light wave does the opposite? What if a light wave passes from a material in which it travels slowly across a boundary and into a material in which it travels fast? The answer to this question can be answered if we reconsider the Marching Soldier analogy. Now suppose that the each individual student in the train of students speeds up once they cross the masking tape. The first student to reach the boundary will speed up and pull ahead of the other students. When the second student reaches the boundary, he/she will also speed up and pull ahead of the other students who have not yet reached the boundary. This continues for each consecutive student, causing the line of students to now be traveling in a direction further from the normal. This is depicted in the diagram below.

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4 0

3 years ago

Label the parts of the respiratory system.

Evgesh-ka [11]

Answer:

1. Nose

2. Mouth

3. Larynx

4. Lung

5. RIght Bronchi

6. Diaphragm

7. Pharynx

8. Trachea

9. Left Bronchi

10. Bronchioles

11. Avoli

Explanation:

8 0

2 years ago