CHEMISTRY HIGH SCHOOL

Boron found in nature has an atomic weight of 10.811 and is made up of the isotopes 10B (mass 10.013 amu) and 11B (mass 11.0093 amu). What percentage of naturally occurring boron is made up of 10B and 11B respectively? a. 30:70
b. 25:75
c. 20:80
d. 15:85

Answers

Answer 1
Answer: C 20:80 because the equation would be (10×.2)+(11×.8)

Related Questions

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The Principle Quantum Number describes what aspect of electron orbitals?a) shape.b) orientation.c) spin.d) energy level.
Which of the following has a positive enthalpy without a temperature change? condensing gas evaporating a liquid cooling a solid cooling a liquid
What is the ratio of sodium ions to bromide ions in neutral sodium bromide?
Suppose that a substance in a beaker is heated over a burner in a science lab. Which observation would most likely indicate that a chemical change has occurred in the substance?1) If the substance is a liquid or solid, an increase in temperature would indicate a chemical change.2) If the substance is a liquid, a change of some of the liquid to gaseous form would indicate a chemical change.3) If the substance is a solid, a change of some of the solid to liquid form would indicate a chemical change.4) If the substance is a liquid or solid, the production of an odor would indicate a chemical change.

A lahar is a type of mudflow that occurs?A. after a volcanic eruption
B. before a hurricane make landfall.
C. after a severe thunderstorm
D. during a tornado

Answers

A lahar is a type of mudflow that occurs after a volcanic eruption. It is a sort of mudflow or trash stream made out of a slurry of pyroclastic material, rough flotsam and jetsam, and water. The material streams down from a fountain of liquid magma, normally along a waterway valley. Lahar is the most deadly by-products of the eruption because of the speed they can travel.

A lahar is a type of mud flow that occurs?  The answer is, A. after a volcanic eruption.

Which statement best describes why specific heat capacity is often more useful than heat capacity for scientists when comparing two materials?Specific heat capacity is an intensive property and does not depend on sample size.
Specific heat capacity is an extensive property and does not depend on sample size.
Specific heat capacity is an intensive property and depends on the sample size.
Specific heat capacity is an extensive property and depends on the sample size.

Answers

The correct option is this: SPECIFIC HEAT CAPACITY IS AN INTENSIVE PROPERTY AND DOES NOT DEPEND ON SAMPLE SIZE.

Generally, all the properties of matters can be divided into two classes, these are intensive and extensive properties. Intensive properties are those properties that are not determined by the quantity of the material that is present or available. Examples of intensive properties are colour, density and specific heat capacity. For instance, whether you have a bucket of water or a cup of water, the quantity does not matter, the colour of water will always remain the same. Extensive properties in contrast, are those properties that depend on the quantity of material that is available. Examples are mass, heat capacity and volume.

Specific heat capacity is defined as the amount of heat required to increase the temperature of 1 gram of a substance by 1-degree Celsius.

The specific heat capacity is more often used for comparing materials, as it is an intensive property. Thus, statement A is correct.

What is the use of Specific Heat Capacity?

Specific heat capacity, which is also referred to as massic heat capacity, is the amount of heat added to 1 gram of mass to raise the temperature by 1-degree Celsius.

Specific heat is an intensive property and is not dependent on the size of the sample. This property of the specific heat is used to compare two materials.

Intensive properties are those properties that are not affected by the quantity of the material. Thus, statement A is correct, Specific heat capacity is an intensive property and does not depend on sample size.

Learn more about specific heat capacity, here: brainly.com/question/13369050

What is the volume of the sample at stp ?

Answers

At stp the volume is 22.4 L .

hope this helps!

Which of the following was NOT a conclusion of Rutherford’s gold foil experiment? a. The atom is mainly empty space
b. The nucleus has a negative charge
c. The atom has a dense nucleus
d. Alpha particles can pass through a thin sheet of gold foil
e. All of the above are correct regarding the gold foil experiment

Answers

The answer is b.) The nucleus has a negative charge

It was not a conclusion because it is neutral. It is not positive nor negative. 

Select all that apply.1: Which of the following particles are of approximately equal mass?

A: protons
B:electrons
C:neutrons
D:quarks
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2: If the atomic number of an element is 16, then it has 16 electrons.

True
False
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3: An unknown substance is tested and found to have the following physical properties:

brittle
fair conductor of electricity
dull (not shiny)

The substance is most likely a _____.

A:metal
B:metalloid
C:nonmetal
D:can not be determined without more data
---------------------------------------------------------------------------------------------------------------------------

Answers

1)Protons and Neutrons have approximately equal masses

2)TRUE

3) B-Metalloid

Answer:

its a and b

Explanation:

i got it right on test

An ore is a rock that contains which of the following? A. a mineral or metal with economic usefulness B. a gemstone only C.a mineral or metal with no practical use D. particles of rock that erode into sediment

Answers

I think the correct answer among the choices presented above is option A. An ore is rock that contains a mineral or metal with economic usefulness. Examples are copper ore, gold ore and iron ore. These ores are being extracted from the Earth by mining.

Answer:

The correct answer is option A. "a mineral or metal with economic usefulness".

Explanation:

An ore is defined as a rock or sediment found in nature which contains a mineral or metal with economic usefulness. The minerals or metals in the ore must be extracted before they could be used, and typically, they are refined via smelting. The ore grade is defined according to the concentration of the mineral or metal beneath the rock or sediment.
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