The density of a material is the mass of the material per unit volume. Here the weight of the same metal is 44.40g, 40.58g and 38.35g having volume 4.8 mL, 4.7 mL and 4.2 mL respectively. Thus the density of the metal as per the given data are, 
= 9.25g/mL, 
= 8.634g/mL and 
= 9.130g/mL respectively.
The equation of the standard deviation is √{∑(x - 
)÷N}
Now the mean of the density is {(9.25 + 8.634 + 9.130)/3} = 9.004 g/mL.
The difference of the density of the 1st metal sample (9.25-9.004) = 0.246 g/mL. Squaring the value = 0.060.
The difference of the density of the 2nd metal sample (9.004-8.634) =0.37 g/mL. Squaring the value = 0.136.
The difference of the density of the 3rd metal sample (9.130-9.004) = 0.126 g/mL. Squaring the value 0.015.
The total value of the squared digits = (0.060 + 0.136 + 0.015) = 0.211. By dividing the digit by 3 we get, 0.070. The standard deviation will be 
. Thus the standard deviation of the density value is 0.265g/mL.
One oxygen atom shares two electron with two hydrogen atoms in this way water molecules are formed. The bond between oxygen and hydrogen is covalent bond.
<h3>What is covalent bond ?</h3>
An electron exchange that results in the formation of electron pairs between atoms is known as a covalent bond. Bonding pairs or sharing pairs are the names given to these electron pairs.
Covalent bonding is the stable equilibrium of the attractive and repulsive forces between atoms when they share electrons.
According to the amount of shared electron pairs, there are three different forms of covalent bonds. single covalent bond is one type of covalent bond. covalent double bond and covalent triple bond.
Thus, option B is correct .
To learn more about covalent bond follow the link ?
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Answer:
283 grams KCl
Explanation:
To convert form moles to grams, you need to find the molar mass of your compound. The molar mass can be calculated using the individual molar masses of each element in the compound. These values can be found on the periodic table.
Molar Mass (K) = 39.098 g/mol
Molar Mass (Cl) = 35.453 g/mol
Molar Mass (KCl) = 39.098 g/mol + 35.453 g/mol
Molar Mass (KCl) = 74.551 g/mol
Now that you know the molar mass, you want to multiply it by the moles of KCl. This is possible because the molar mass is actually a ratio representing the relationship of grams and moles. In KCl, there are 74.551 grams of KCl for every 1 mole of KCl. When you are multiplying, make sure you set the ratio up in a way that allows for the units to cancel out and leave grams as your final answer.
3.80 moles KCl 74.551 g
----------------------- x ------------------- = 283 grams KCl
1 mole KCl
The final answer should have 3 sig figs because the value the problem gave (3.80 mol) also has 3 sig figs.
Answer:
The answer to your question is 5.019 x 10²² atoms
Explanation:
Data
mass of ammonium carbonate = 8 g
number of atoms = ?
Process
1.- Calculate the molar mass of (NH₄)₂CO₃
(NH₄)₂CO₃ = (14 x 2) + (1 x 8) + (12 x 1) + (16 x 3)
= 28 + 8 + 12 + 48
= 96 g
2.- Calculate the number of atoms
96 g ------------------ 6.023 x 10²³ atoms
8 g ----------------- x
x = (8 x 6.023 x 10²³) / 96
x = 5.019 x 10²² atoms
