Sodium has has 11 protons, 11 electrons and 12 neutrons.
<h3>What is the periodic table?</h3>
The periodic table shows the elements as they are arranged in increasing atomic number. The elements on the left hand side of the table are metals. Those on the right hand side of the table are mostly nonmetals.
A element in the first column is sodium;
The element Na is called sodium and it belongs to group 1 elements. It has 11 protons, 11 electrons and 12 neutrons.
Learn ore about sodium:brainly.com/question/24010534
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Option B: 4.3
There are following rules for rounding off numbers:
1. If the rounding digit has digit less than 5 (1,2,3 and 4) to its right, all the digits on right side of the rounding digit will drop out.
2. If the rounding digit has digit equal and greater than 5 (5,6,7,8 and 9) to its right, one is added to the rounding digit.
Jeff has to weigh 4.312 g sample of NaCl. To round off the underline number 4.<u>3</u>12, check for the digit right to it. It has 1, which is less than 5 thus according to the Rule 1, all the digits on right side of the rounding digit will drop out and the number gets rounded off to 4.3.
Therefore, 4.3 is most accurate measurement by Jeff.
White phosphorus burns spontaneously in chlorine to produce a mixture of two chlorides, phosphorus (ii) chloride and phosphorus(v) chloride and heat is evolved. Phosphorus (iii) chloride is a colorless fuming liquid:
P4 + 6Cl2 = 4PCl3
Phosphorus (v) chloride is an off-white solid
P4 +10Cl2 = 4PCl5
1 ) J.J. Thompson discovered the electron and put forward the 'plum pudding model' with charges spread evenly throughout the atom, in 1897
so the correct answer would be a positive solid sphere with electrons dispersed throughtout
Answer:
- <u>The container must be built of lead, and it should be kept in a concrete vault.</u>
Explanation:
The goal is to contain the <em>gamma rays</em> to<em> reduce</em> the <em>exposure </em>to their harmful <em>radiation</em>.
The gamma rays are the most energetic electromagnetic radiation: they have the smallest wavelength, the largest frequency, and the largest energy from all the electromagnetic radiations.
Due to that, only very dense substances like lead and concrete can stop the gamma rays. In the case of concrete, large blocks with thick walls are required.
Thus, in a lab the best container for a sample of uranium - 238 that is decaying, emitting gamma rays, must be built of lead, and enclosed in a conrete vault.
