3. compounds in which elements are held together by covalent bonds...keeps their own properties
A polar molecule
B. element
C. compound
D. molecule

Answer:7.72 years

Nuclear half-life expresses the time required for half of a sample to undergo radioactive decay.

Explanation:

0.01 = 67.0 ×[tex](\frac{1}{2}) ^{\frac{98.0} {1/2 } }[/tex] [tex]\frac{0.01}{67.0}[/tex] = 0.000149=[tex](\frac{1}{2}) ^{\frac{98.0} {1/2 } }[/tex]

[tex]^{\frac{98.0} {1/2 } }[/tex] =log[tex]_{0.5}[/tex] (0.000149)=12.7

[tex]^{\frac{98.0} {1/2 } }[/tex]=7.72 years

Hope this helps have a great day/afternoon :)

Answer:365 days, 5 hours, 59 minutes and 16 seconds.

Answer:

I think its b. if not sorry but its the one that makes most sense

Explanation:

Answer:

B

Explanation:

Hope this helps you have a nice day!

Answer:

2.41×10²³ molecules of water

Explanation:

Given data:

Mass of methane = 3 g

Molecules of water formed = ?

Solution:

Chemical equation:

CH₄ + 2O₂    →     CO₂  + 2H₂O

Number of moles of methane:

Number of moles = mass/ molar mass

Number of moles = 3 g/ 16 g/mol

Number of moles = 0.2 mol

Now we will compare the moles of water with methane.

               CH₄           :              2H₂O

                  1              :                  2

                0.2            :             2 × 0.2 = 0.4 mol

Molecules of water:

1 mole = 6.022×10²³ molecules of water

0.4 mol ×6.022×10²³ molecules of water / 1mol

2.41×10²³ molecules of water

Answer:

H20

Explanation:

Answer:

hope it helped you

Explanation:

H2O (u have to write ✍️no 2 below H.

Answer:

make a new friend if you lose one, Its part of life losing people thats what make us people grow and be more mature.

Answer:

A. cars, submarines, spacecraft

Explanation:

I took the test.

Answer:

D = m/v

Explanation:

So m = 24g and v = 16mL. (I assume these are the units being used). Then, we get D = 24g/16mL which is 1.5 g/mL

Answer:

a free-falling object is an object that is falling under the sole influence of gravity. That is to say that any object that is moving and being acted upon only be the force of gravity is said to be "in a state of free fall." Such an object will experience a downward acceleration of 9.8 m/s/s.

Answer: A

Explanation:

Answer:

The answer is A

Explanation:

Answer: At STP, one mole (6.02 × 1023 representative particles) of any gas occupies a volume of 22.4 L (Figure below). A mole of any gas occupies 22.4 L at standard temperature and pressure (0°C and 1 atm).

Explanation:

That the answer

1 mole of a gas occupies 22.4 L at (0°C and 1 atm). It is the standard temperature and pressure.

Avogadro's hypothesis says that all gases have an equal number of particles at the same temperature and pressure.

The empty space between the particles makes up the majority of a gas's overall volume.

Due to this, the size of the particles themselves is nearly insignificant.

The volume of one mole of a gas at standard temperature and pressure is known as the molar volume.

Thus, the correct option is 0°C and 1 atm.

Learn more about Avogadro's hypothesis

https://brainly.com/question/12779877

Answer:

volume of 200mL, density shows it weighs .789 grams for every mL.  .789*200= 157.8 grams

Explanation:

Answer:

Elements to the left of the line are considered metals. Elements just to the right of the line exhibit properties of both metals and nonmetals and are termed metalloids or semimetals. Elements to the far right of the periodic table are nonmetals. The exception is hydrogen (H), the first element on the periodic table.

Explanation:

Answer:

looking at its metallic luster

Explanation:

Elements may be classified as either metals or nonmetals based on their properties. Much of the time, you can tell an element is a metal simply by looking at its metallic luster, but this isn't the only distinction between these two general groups of elements. Most elements are metals.

Answer:

A cold front is a boundary or zone that separates two air masses. The cooler more dense mass replaces the warmer.

hope this helps :)

Explanation:

Answer:

A cold front is a boundary or zone that separates two air masses. The cooler more dense mass replaces the warmer.

Explanation:

i am smart.....( i think )

Answer:

i think its D

Explanation:

The law of conservation of mass or principle of mass conservation states that for any system closed to all transfers of matter and energy, the mass of the system must remain constant over time, as the system's mass cannot change, so quantity can neither be added nor be removed.

Taking into account the law of conservation of mass,

The Law of Conservation of Matter is also called the law of conservation of mass or the Law of Lomonósov-Lavoisier. This law postulates that "The mass is not created or destroyed, only transformed."

This means that the reagents interact with each other and form new products with different physical and chemical properties than those of the reagents. And this is because the atoms of the substances are ordered differently.

But the quantities of the masses involved in a given reaction must be constant throughout it, that is, they will not have changed in their proportions when the reaction ends. Then the mass before the chemical reaction is equal to the mass after the reaction.

The exception to the rule is nuclear reactions, in which it is possible to convert mass into energy and vice versa.

Finally, the correct answer is option A. because the atoms of the substances are ordered differently, this is the reagents interact with each other and form new products.

Learn more about law of conservation of mass:

Answer:

Please upload the picture and I can answer

Explanation:

Answering: it is mostly empty space

Explanation:

Answer:

1.A 2.B

Explanation:

your welcomme glade to help

Answer:

the answer is coefficient

Answer:

Coefficient is your answer

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I beleive it would be 0.8

the volume of water alone is 4.8

the volume of rock and water is 5.6

you would subtract them both to find the volume of the Rock.

Answer:

1- if one component in a series circuit fails, then all the components in the circuit fail because the circuit has been broken.

2-  the more components there are in a series circuit, the greater the circuit's resistance

Answer:

Detail is given below.

Explanation:

Chemical equation:

4NH₃ + 3O₂      →     2N₂ + 6H₂O

This reaction shows that when ammonia react with oxygen it form water and nitrogen gas.

There are two reactants on left hand side oxygen and ammonia. Ammonia is formed when nitrogen and hydrogen react. While on right hand side there are two products nitrogen and water. Water is formed by the reaction of hydrogen and oxygen.

The given reaction also shows that it follow the law of conservation of mass.

According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.  

This law was given by French chemist  Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.

D: the thermal energy is moving from the ice cube into the water causing the temperature of the water to decrease.​



Answer:

Because too much Carbon Dioxide can kill us.

Explanation:

Answer: Volume of rectangle = L * W * H

Explanation: Multiply the 3 numbers together

Answer:

volume = L x W x H

V= 17 x 7.5 x 0.8

V = 102 cm^3

Explanation: Multiply the three number.

To find the volume, you multiply length times width times heigh

Answer:

True I think..-

Explanation:

Sorry if it's wrong.-

Answer:A measure of performance of fuel for internal combustion engines. Stated simply, a higher octane rating corresponds to more engine power and less knocking or other pre-ignition problems.

Explanation:

I'm also in chemistry.

Answer:

Explanation:

figure indicating the antiknock properties of a fuel, based on a comparison with a mixture of isooctane and heptane.

Answer:

it is alkali

Explanation:

hope it helps you