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Masja [62]
3 years ago
15

The period 4 alkaline-earth metal has the name_______ . An isotope of this element having 20 neutrons has amass numberof _______

Chemistry
1 answer:
Cerrena [4.2K]3 years ago
6 0

Answer:

The period 4 alkaline-earth metal has the name Calcium. An isotope of this element having 20 neutrons has a mass number of 40.

Explanation:

Looking at the periodic table 4th row for the alkaline-earth metal, we can find Calcium which has an atomic number of 20 (or protons number, or z). The mass number is given by the sum of protons and neutrons. If the number of protons in this case is 20 and the number of neutrons is also 20, the mass number A = 40.

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Answer:

Check Explanation

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Explanation:

English Translation

What is the relationship and the PROPORTIONS between Joules, lime, Cal, and Kcal?

Joules is the SI unit of Energy (heat energy).

Calorie, also called lime, is the amount of heat required to raise the temperature of 1 gram of pure water by 1°C or 1 K.

1 calorie = 4.186 J

A thousand calorie is equal to 1 kcal.

Hence,

1 kcal = 1000 calories = 4186 J

In Portugese/Em português

Joules é a unidade SI de energia (energia térmica).

Caloria, também chamada de cal, é a quantidade de calor necessária para elevar a temperatura de 1 grama de água pura em 1°C ou 1 K.

1 caloria = 4,186 J

Mil calorias é igual a 1 kcal.

Portanto,

1 kcal = 1000 calorias = 4186 J

Hope this Helps!!!

Espero que isto ajude

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