CHEMISTRY HIGH SCHOOL

How many cases of measles would you predict were reported last year

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Answer 1
Answer: In the laws of mathematics, especially in rounding off digits, you should take note of the digit following that number no matter how long or short a number is. If the numberis preceded by numbers between 0-4, the number does not change. However if its is preceded by numbers between 5-9, add one to the number. For example, 145698. If it is rounded off to the nearest hundreds, since 9 is the number after 6, add 1 to 6 and it becomes 145700. If it is rounded off to the nearest hundred thousands, since 4 is the number after 1, you do not add, the number stays the same and it becomes 100000

Related Questions

If one ball with a momentum of 50 kg·m/s hits a ball at rest and no other forces are acting on either ball, what's the total momentum of both balls after the collision? A. 0 kg·m/s B. 25 kg·m/s C. 100 kg·m/s D. 50 kg·m/s
A sample composed only of atoms having the same atomic number is classified as(1) a compound (3) an element(2) a solution (4) an isomer
If element x has 55 protons how many electrons does it have
Hot water ____.a) has a higher pH value than cold water b) holds less dissolved oxygen than cold water c) is beneficial to living organisms in aquatic ecosystems d) contains more hydrogen than cold water
A gas is initially at a pressure of 225 kPa and a temperature of 245 K in a container that is 4.5 L. If the gas is compressed to a volume of 2.1 L and the temperature changes to 275 K, what is the new pressure?

At STP, solid carbon can exist as diamond and graphite. Compared to the molecular structure and chemical properties of diamond, graphite has(1) a different molecular structure and different properties
(2) a different molecular structure and the same properties
(3) the same molecular structure and different properties
(4) the same molecular structure and the same properties

Answers

The answer is (1) a different molecular structure and different properties. The graphite has a molecular structure of layer and in the diamond, each atom are bonded strongly to four adjacent carbon atoms which formed a three-sided pyramid. 

Answer is: (1) a different molecular structure and different properties.

Different forms of the same element that have different properties because of different atom arrangements are called allotropes.

Carbon has many allotropes, but two most important are graphite and diamomd.

Graphite has sp2 and diamond has sp3 hybridization of carbon atoms, because of that graphite conduct electricity and diamond not.

In diamond carbon atoms are arranged in the face centered cubic crystal structure called a diamond lattice.  

Diamond has very strong covalent bonds between carbon atoms and because of that it has the highest hardness and thermal conductivity of any bulk substance.

How many grams of lithium nitrate will be needed to make 250 grams of lithium sulfate

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313.03, since every molecule of lithium nitrate produces 1 lithium, where lithium sulfate consumes double, then you find that the moles of lithium sulfate are 2.27 (mass/molar mass), then multiply that by 2 (for the discrepancy in the molecule consumption/production) and then multiply that by the molar mass of lithium nitrate to find the mass of lithium nitrate needed. Hope that helped.

When iron rusts in air, iron (III) oxide is produced. How many moles of oxygen react with 2.4 mol of iron in the rusting reaction shown below ?

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the answer is 2.4*3/2 = 3.6 mol o2

Which is true about the temperature of a gas?At a higher temperature, the particles have a higher average kinetic energy.
At a higher temperature, the volume of the gas is smaller.
At a lower temperature, there are more particles in the gas.
At a lower temperature, the particles in the gas move faster.

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The statement that true about the temperature of a gas is at  a higher temperature, the particles have a higher average kinetic energy. The rest of the choices do not answer the question above.

Answer:

A

Explanation:

Took the test Got it right

A scientist would most likely need to update her model when?

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A scientist would most likely need to update his / her model when it no longer supports the latest results. This could mean that the scientist's model is shrinking or growing, thus, he / she has to update them. Updating them would also make the model appear more interesting.

What are geometric isomers?

Answers

each of two or more compounds that differ from each other in the arrangement of groups with respect to a double bond, ring, or other rigid structure.
Other Questions
Which of the following is not a type of adaptation? A. Functional B. Mechanical C. Behavioral D. Structural
What is the empirical formula for a compound if a sample contains 3.72g of P and 21.28g of Cl?
What is the nuclear equation for the alpha decay of 173 Yb?
If a catalyst is used in a reaction:a. the energy of activation increases. b. the reaction rate does not change. c. the reaction rate increases. d. the equilibrium shifts.