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mr_godi [17]
2 years ago
15

What are the elements in the first period

Chemistry
2 answers:
aliina [53]2 years ago
6 0

Answer:

Explanation:

There are only two elements in the first period: hydrogen and helium. We can explain why there is less elements in the first row in modern theories of atomic structure.

Bond [772]2 years ago
6 0

Answer:

"Hydrogen and Helium". Hydrogen and Helium are the elements of the first period in the modern periodic table.

Explanation:

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Why are environmental factors important to consider when assessing an individual’s health?
lisabon 2012 [21]

Answer: c. Some health risks are increased by heredity, which manifest under certain environmental conditions.

Explanation:

Many abiotic factors (non-living factors) such as radiations, hazardous substances present in the environment such as air, water and soil may originate from the industries, mining practices, fossil fuels and landfills. Some of the substances are carcinogenic and mutagenic in nature. These are capable of affecting the genetic make up of the organism. The genetic variations or mutations occurs may transmit from the parent to the offsprings.

Therefore, on the basis of the above information, c. Some health risks are increased by heredity, which manifest under certain environmental conditions. is the correct option.

3 0
3 years ago
Read 2 more answers
A decay series starts with the synthetic isotope ²³⁹₉₂U. The first four steps are emissions of a β⁻ particle, another β⁻, an a p
VladimirAG [237]

<u>Thorium series</u> could start by this sequence.

<h3>Brief explanation</h3>

To write balanced equations for nuclear decay processes. It's important to remember that the mass number and the atomic numbers must be balanced. And so what that means is that if we look at an elements nuclear symbol, the atomic number is the bottom number and the top number, the superscript, is the mass number, and so when we add them up on both sides, they have to be equal. There are two different ways in which decay can occur.

In this, series one is through beta decay, which means that the following particle is produced. The other is Alpha Decay, which produces this particle. Both are products. So if we start off with uranium to 39 you read it in nuclear notation, which means we have to find the atomic number just 92 and it undergoes beta decay.

So that means that it produces this particle find the second particle we used the atomic number, so 92 equals minus one plus x, where X equals 93 which is Neptune IAM. The mass number of our new isotope is zero plus X equals to 39 where X equals to 39. This product becomes the reactant in my next decay, which is also a beta decay. And to find the unknown element we do the same here.

Except for that it's 93 equals minus one plus x, where X is 94 which is P u plutonium, and the mass number is zero plus X equals to 39 or to 39. The next decay starts with the isotope that we just form to 39 p. U. This time it's an Alpha decay. So we produce this particle to find the unknown. Element 94 equals two plus x, where X equals 92 which takes us back to uranium.

Find the mass number of this isotope 2 39 equals four plus X, where X equals to 35. Finally, for the last decay, you have another Alpha decay starting with uranium to 35 making an alpha particle. The atomic number will be 90 which is T H and the top is 2 31 For the mass number. This begins the natural decay, series of thorium .

Learn more about chemical decay

brainly.com/question/1898040

#SPJ4

7 0
9 months ago
How did oxygen first enter Earth's atmosphere?
forsale [732]

Answer:

I think c biological processes

8 0
2 years ago
Balance the following chemical equation by providing the correct coefficients fe+h2so4 fe(so4)3 + h2
Dmitriy789 [7]

Answer:

2Fe + 3H2SO4 + Fe2(SO4)3+ 3H2

Explanation:

1. Fe (SO4) 3 is an incorrectly written formula because iron is trivalent as we can see by this three ahead of SO4. SO4 is divalent always.

2. since (SO4) is 3, this three shows us that there must be 3 in the reactants as well.

so now there is 3H2SO4

3. Since we have added 3 to one hydrogen we must add another. So now it's 3H2

4. and finally iron. In Fe2 (SO4) 3 we see this 2 in front of Fe which means it goes 2Fe.

3 0
2 years ago
What type of atom is hydrogen with an atomic mass of 1 and 2 electrons
Charra [1.4K]

Answer:

This would be the hydride ion where H gains an electron from a metal such as  Na

Explanation:

7 0
3 years ago
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