Question

!!!СРОЧНО!!!нужен доклад по химии. по элементу "кальций"​(пожалуйста, без приколов) ​

Answer 1

Ответ:

Ка́льций (Ca от лат. Calcium) — элемент второй группы (по старой классификации — главной подгруппы второй группы), четвёртого периода, с атомным номером 20. Простое вещество кальций — мягкий, химически активный щёлочноземельный металл серебристо-белого цвета. Впервые получен в чистом виде Г. Дэви в 1808 году.

Кальций

← Калий | Скандий →

20 Mg

↑

Ca

↓

Sr

Периодическая система элементов

20CaCubic-face-centered.svgElectron shell 020 Calcium.svg

Внешний вид простого вещества

Умеренно твёрдый[1], серебристо-белый металл

Calcium unter Argon Schutzgasatmosphäre.jpg

Кальций в атмосфере аргона

Свойства атома

Название, символ, номер

Ка́льций/Calcium (Ca), 20

Атомная масса

(молярная масса)

40,078(4)[2] а. е. м. (г/моль)

Электронная конфигурация

[Ar] 4s2

Радиус атома

197 пм

Химические свойства

Ковалентный радиус

174 пм

Радиус иона

(+2e) 99 пм

Электроотрицательность

1,00 (шкала Полинга)

Электродный потенциал

−2,76 В

Степени окисления

2

Энергия ионизации

(первый электрон)

589,4 (6,11) кДж/моль (эВ)

Термодинамические свойства простого вещества

Плотность (при н. у.)

1,55 г/см³

Температура плавления

1112 К; 838,85 °C

Температура кипения

1757 К; 1483,85 °C

Уд. теплота плавления

9,20 кДж/моль

Уд. теплота испарения

153,6 кДж/моль

Молярная теплоёмкость

25,9[3] Дж/(K·моль)

Молярный объём

29,9 см³/моль

Кристаллическая решётка простого вещества

Структура решётки

кубическая гранецентрированная

Параметры решётки

5,580 Å

Температура Дебая

230 K

Прочие характеристики

Теплопроводность

(300 K) (201) Вт/(м·К)

Номер CAS

7440-70-2

Эмиссионный спектр

Calcium Spectrum.png

20

Кальций

Ca40,078

4s2

Объяснение:

надеюсь понятно

Answer 2

Объяснение:

Кальций один из самых элементов из таблици

Менделеева.

Этот элемент содержит в нас как образ жизни наших клеток и костей.

Чтобы улучшить кальций в нашем теле

Надо пить и есть что-то молочное.

Answer 3

Calcium: An Overview

Calcium is a chemical element with the symbol Ca and atomic number 20. It is an essential mineral that plays a crucial role in various biological processes in the human body. Calcium is the fifth most abundant element in the Earth's crust and is commonly found in rocks, minerals, and the shells of marine organisms.

Properties of Calcium

Physical Properties: - Calcium is a soft, silvery-white alkaline earth metal. - It has a melting point of 842°C (1548°F) and a boiling point of 1484°C (2703°F). - Calcium is a good conductor of electricity and heat. - It is relatively reactive and can react with water to produce calcium hydroxide and hydrogen gas.

Chemical Properties: - Calcium is highly reactive and readily forms compounds with other elements. - It reacts vigorously with oxygen to form calcium oxide (CaO) and calcium peroxide (CaO2). - It reacts with halogens, such as chlorine and bromine, to form calcium halides. - Calcium also reacts with acids to produce salts and hydrogen gas.

Occurrence of Calcium

Calcium is one of the most abundant elements in the Earth's crust. It is primarily found in the form of calcium carbonate (CaCO3) in rocks, limestone, chalk, and marble. Calcium is also present in various minerals, such as gypsum (calcium sulfate), fluorite (calcium fluoride), and apatite (calcium phosphate).

In addition to its presence in the Earth's crust, calcium is an essential element for living organisms. It is a vital component of bones, teeth, and shells. Calcium ions also play a crucial role in cellular signaling, muscle contraction, nerve function, and blood clotting.

Uses of Calcium

1. Building Materials: Calcium compounds, such as limestone and gypsum, are widely used in the construction industry for making cement, mortar, and plaster.

2. Dietary Supplement: Calcium is an essential nutrient for the human body. It is necessary for the development and maintenance of strong bones and teeth. Calcium supplements are commonly used to prevent or treat calcium deficiency.

3. Metal Alloys: Calcium is used as an alloying agent in the production of various metals, including aluminum, copper, and lead. Calcium-aluminum alloys are used in the automotive and aerospace industries.

4. Deoxidizer: Calcium is used as a deoxidizer in the production of steel and other metals. It helps remove impurities, such as oxygen and sulfur, from molten metal.

5. Fertilizer: Calcium compounds, such as calcium carbonate and calcium nitrate, are used as fertilizers to improve soil fertility and promote plant growth.

Safety and Health Considerations

While calcium is an essential nutrient for the human body, excessive intake of calcium supplements can lead to hypercalcemia, a condition characterized by high levels of calcium in the blood. This can cause symptoms such as nausea, vomiting, constipation, and kidney stones. It is important to follow recommended daily calcium intake guidelines and consult a healthcare professional before taking calcium supplements.

Conclusion

In summary, calcium is a chemical element with various important properties and uses. It is an essential nutrient for the human body, plays a crucial role in biological processes, and is widely used in industries such as construction, metallurgy, and agriculture. However, it is important to consume calcium in moderation and seek professional advice for supplementation to maintain optimal health.

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