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mr_godi [17]
3 years ago
15

What are the elements in the first period

Chemistry
2 answers:
aliina [53]3 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]3 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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I have five less protons than the least massive metalloid in<br> the fourth period. Who am I?
exis [7]

Answer:

You are the Cobalt

Explanation:

The least massive metalloid in the fourth period is Germanium, and it have 32 protons. If you have 5 less protons: 32 - 5 = 27 protons. The element with 27 protons is Cobalt

6 0
2 years ago
PLEASE ANSWER NOW!!!!! WILL GIVE BRAINLIEST!!!
oee [108]

Answer:

a

b

Explanation:

5 0
3 years ago
. If the half-life of cesium-133 is 30 years, how much of a 600g sample of cesium-133 will be left after
e-lub [12.9K]

Answer:

Caesium (55Cs) has 40 known isotopes, making it, along with barium and mercury, one of the elements with the most isotopes. The atomic masses of these isotopes range from 112 to 151. Only one isotope, 133Cs, is stable. The longest-lived radioisotopes are 135Cs with a half-life of 2.3 million years, ... It constitutes most of the radioactivity still left from the Chernobyl accident ...

3 0
2 years ago
how to determine the aspects for core and valence electrons in a periodic table. How comes in some elements like cobalt the 3d i
dusya [7]

Answer:

See explanation

Explanation:

The electron configuration of an atom in an element determines the property of the atom. The core electrons are found inside the atom while the valence electrons are found on the outermost shell of the atom.

For cobalt, the outermost shell electron configuration is; [Ar] 3d7 4s2. The 3d7 and 4s2 are found in the valence shell of cobalt.

For arsenic, the electronic configuration is [Ar] 3d¹⁰ 4s² 4p³. The valence electrons are 4s2, 4p3. The 3d electrons are found inside the arsenic atom.

5 0
2 years ago
What is 5 ounces in milliliters?
SIZIF [17.4K]
1 ounces ----------- 29.5735 mL
5 ounces ----------- ??

5 x 29.5735 / 1 => 147.868 mL

hope this helps!
6 0
2 years ago
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