1.5 metres is the length of the tape. Hope this helps :)
A compound consists of 2 or more elements that are combined chemically in such a way that the elements themselves can no longer be identified by their individual properties. So the Answer is A.
You did not include the questions.
I did some research and found the questions:
<span>
What is the mass of 1 mole of pennies?
How many moles of pennies have a mass equal to the mass of the moon?
Solutions:
1) mass of 1 mole of pennies
Data: mass of 1 penny = 2.50 g
1 mole = 6.022 * 10^ 23 units
Proportion:
1 penny 6.022 * 10^23 penny
-------------- = ----------------------------
2.50 g x
Solve: x = 6.022 * 10^23 penny * 2.50g / 1 penny = 15.055* 10^23
Since 2.50 has 3 significant figures, the answer must use 3 significant figures => x = 15.1 * 10^ 23 g = 1.51 * 10^24 g
Answer: 1 mol of pennies have a mass of 1.51 * 10^24 g
2) How many moles of pennies have a mass equal to the same mass of the Moon
Convert the mass of the Moon grams: 7.35 * 10^22 kg = 7.35 * 10^ 25 g
1 mol x
---------------------- = ----------------------
1.51 * 10^ 24g 7.35 * 10^ 25 g
=> x = 7.35 * 10^ 25 g * 1 mol / (1.51 * 10^24 g)= 48.7 mol
Answer: 48.7 mol
</span>
Answer:
Avogadro’s number was calculated by determining the number of atoms in 12.00 g of carbon-12.
Explanation:
The number of particles presents in one mole of a substance is known as Avogadro's number.
Avogadro's number is 
atoms or molecules or ions or particles present in one mole of a substance. It is denoted by the symbol 
or 
. It is a dimensionless quantity.
Avogadro's number was proposed by Jean Perrin but named in the honor of italian scientist Amedeo Avogadro.
Avogadro's number is the number of atoms present in 12 grams of carbon-12.
Here we have to get the right answers which include the given phrase.
The correct answers are as following:
High boiling and melting points: Hydrogen bond increase the amount of energy required for phase changes to occur, thereby raising the boiling and melting points.
High specific heat: Hydrogen bond increase the amount of energy required for molecules to increase the speed, thereby raising the specific heat.
High surface tension: Hydrogen bonds produce strong inter molecular attractions, which increase surface tension.
The incorrect answer:
Lower density as a solid than as a liquid: actually, density of solid is more than density of liquid as hydrogen bonds in solid produce strong inter molecular attractions among molecules, which aggregates molecules together, hence volume of associated molecules reduces. Therefore, density of solid is more than that of liquid.
