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guajiro [1.7K]
3 years ago
9

A cual grupo pertenecen las tierras raras y los elementos representativos??​

Chemistry
1 answer:
lidiya [134]3 years ago
4 0

Answer:

Explanation:

2

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Which statement identifies the element arsenic?
insens350 [35]

Answer : Option A) Atomic number of Arsenic is 33.


Explanation : Arsenic contains same number of protons in its atomic nucleus. In arsenic there are 33 protons found in the atomic nucleus. Hence, the atomic number will be 33. It has 5 valence electrons in its outermost shell, which is also called as valence shell. So, its valency becomes 5.

8 0
3 years ago
Read 2 more answers
How many molecules are in 18moles of CH.​
-Dominant- [34]

Answer:

1.08 x 10²⁵molecules

Explanation:

From the mole concept we know that ;

      1 mole of any substance contains 6.02 x 10²³ molecules

This number is the Avogadro's number.

 So;

  18 mole of CH will contain:

       Number of molecules of CH  = 18 x 6.02 x 10²³ = 1.08 x 10²⁵molecules

The number of molecules is therefore 1.08 x 10²⁵molecules

8 0
3 years ago
Consider a 100-gram sample of radioactive cobalt-60.
svetlana [45]

It will take 5.2 years to decay.

The half life of cobalt-60 is 5.2 years. The half life is the time taken for the mass of the substance to decrease by a half.

here, the amount of remaining substance is 50%,

so, (\frac{1}{2} )^{n} = 0.5

n. log (0.5) = log (0.5)

n = 1

So it would take 1 half lives to decay this much, which is 1 x 5.2 which is 5.2 years.

what do you mean by radioactive decay ?

The process through which an unstable atomic nucleus loses energy via radiation is known as radioactive decay, also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration. A material that has unstable nuclei is considered as radioactive.

Learn more about decay here:-

brainly.com/question/13853996

#SPJ1

7 0
2 years ago
Why there are only 20 amino acids, although a amino acid is coded by a single codon with three bases. That means by permutation,
snow_lady [41]
In nature there are many more variations amino acids than the simple 20 found in humans. However, when analyzing the human genome sequence, there is a code for all 64 permutations (4^3), only some of them share amino acids. This is a safe-guard against mutations of one or two nucleotides. For example, the amino acid Alanine is coded with four different nucleotide sequences: GCA, GCC, GCG, GCU. Also some amino acids code the same like UUU &UUC
5 0
3 years ago
A 2.04 g lead weight, initially at 10.8 oC, is submerged in 7.62 g of water at 52.3 oC in an insulated container. clear = 0.128
alisha [4.7K]

Answer: The final temperature of both the weight and the water at thermal equilibrium is 50.26^{o}C.

Explanation:

The given data is as follows.

mass = 7.62 g,           T_{2} = 10.8^{o}C

Let us assume that T be the final temperature. Therefore, heat lost by water is calculated as follows.

       q = mC \times \Delta T    

          = 7.62 g \times 4.184 J/^{o}C \times (52.3 - T)

Now, heat gained by lead will be calculated as follows.

       q = mC \times \text{Temperature change of lead}  

           = 2.04 \times 0.128 \times (T - 11.0)

According to the given situation,

     Heat lost = Heat gained

7.62 g \times 4.184 J/^{o}C \times (52.3 - T) = 2.04 \times 0.128 \times (T - 11.0)

        T = 50.26^{o}C

Thus, we can conclude that the final temperature of both the weight and the water at thermal equilibrium is 50.26^{o}C.

7 0
3 years ago
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