Calculate the amount of heat needed to evaporate 235.0 grams of water from 25.0°C to 100.0°C.

Answer:

Calculate the rate of decay constant for U-238 if its half-life is 4.468 × 109 years. Answer: If the problem is referring to the half-life, then the ratio of = 0.5 because half of the original sample has already undergone decay.

Explanation:

Answer:

The frequency of Wave 2 is double the frequency of Wave 1.

Explanation:

Waves with higher frequencies have shorter wavelengths, and lower frequencies have longer wavelengths.

The correct statement is B. Three molecules of N₂ should be produced during the decomposition. :)

Answer: b

Explanation: I took the quiz

Answer: 3

Explanation:

Answer:

kinetic energy

Explanation:

may be iam not sure

Answer:

helium is denser than air

Answer:

For air, which has a molar mass of 29.0 g/mol, this gives a density of 1.18 g/l. Helium, which has a mass of 4.00 g/mol, has a density of 0.164 g/l.

Answer:

Electrons

Explanation:

When determining the chemical properties of elements, the most important subatomic particle to consider is the electrons.

Electrons are negatively charged particles that orbits an atom. They occupy the extranuclear space of an atom.

These electrons determines the chemical properties of each atom. Most especially, the valence ones. All elements wants to resemble the noble gases, so they alter their number of electrons in order to attain this stable state.

Answer:

photosynthesis occurs so the plants can create energy from carbon dioxide and sunlight.  

Explanation:

so basiclly it occurs so the plants can create energy to stay alive.

Answer:

Explanation:

photosynthesis occurs basically to help plants get light in order to produce its necessary daily production of nutrients needed for animals to get carbohydrates froms which is eaten by animals since it gives energy. so basically photosynthesis--> energy --> carbs for mammals to eat!

the green colour reflects off the plant so it is not absorbed by the chloroplasts  rather all colours are absorbed just not green.

and every organic material on earth is produced by these cells which convert energy from the sun into nutrient filled plants.. its essential for the CO2 cycle ,  and since they conduct photo synthesis they are lowest level in the food chain so basically its important since they create nutrients for our plants.

Dipole-dipole interactions are the strongest intermolecular pressure of attraction.

Answer: Dipole-dipole interactions are the strongest intermolecular force of attraction.

Explanation:

Answer:

Yes, Copper (Cu) in its pure form is a reddish-brown metallic element with high ductility and malleability that is an excellent conductor of heat and electricity: atomic weight 63.54; atomic number 29; density 8.94 g/cm3; melting point 1083°C; and boiling point 2595°C.

Answer:

no ,its not malleable

Explanation:

copper II sulphate is a blue compound , which is brittle solid , crystalline .

copper metal is malleable and ductile

Answer:

Electromagnets are only functional when electricity is passing through them. In other words, they only create a magnetic field when there is an electric current flowing.

A power source like a battery is therefore necessary to supply the electric current necessary for the magnet to work however, it will not work unless the circuit is closed as electricity cannot not flow in an open circuit because current needs to be able to flow from one end of a power source to the other end.

Explanation:

ha hot dog hamburger hamburger ng baboy hahaha bomba girl home baboy

Answer:

D

Explanation:

All of the above are great examples!

"Endothermic reactions are those which absorb heat during the reaction."

Answer:

Energy is required to break bonds in a molecule and released when bonds are made.

Explanation:

Energy is added to break bonds and released when making bonds.

Answer:

chemistry

Explanation:

Answer:A substance must absorb heat energy so that it can melt or boil. The temperature of the substance does not change during melting, boiling or freezing - even though energy is still being transferred

Explanation:imm not sure

Answer:

aluminum

Explanation:

oxygen's atomic number is 8.

aluminum's atomic number is 13.

The mass of one electron : 9.103 x 10⁻²⁸ g

Electrons are a part of the atomic nucleus particles (including protons and neutrons), and are negatively charged (-1)

An electron has the charge of  -1.6022 x 10⁻¹⁹C

1 g =  -1.76 x 10⁸ C

so the mass of one electron :

[tex]\tt \dfrac{1.6022\times 10^{-19}}{1.76\times 10^8}=9.103\times 10^{-28}~g[/tex]

Answer:

Topping the list of concerns is hydrogen burns. In the presence of an oxidizer -- oxygen is a good one -- hydrogen can catch fire, sometimes explosively, and it burns more easily than gasoline does.

Answer:

hydrogen burns

hope it helps

Answer:

24 is the answer of this question

Answer:

The validation of seafloor spreading in the 1950s and 60s

Explanation:

The theory of seafloor spreading was supported by numerous evidence including thermal probes that showed that heat flow over the mid-ocean ridges measured up to four times those measured in general bottom sediments, which are taken as due to the presence of molten Earth material close to the ridge crest

The ridge crest also show signs unusually seismic wave velocities that are considered to be due to microfracturing and thermal expansion from upwelling magma

Answer:

0.03:---$7--$-$7$--$-$-$$-$+-$$7-$$-$7-$8$+$-$

Answer:

the action or process of filtering something or in chemistry separating suspended solid matter from a liquid causing latter to pass through the pores is some substance

Answer: b

explanation: i had the question on a test and got it right.

Answer:

I Would bc it's the better opportunity

Answer:around 7

If your dish soap is labeled mild, gentle, or great for hands, chances are its pH level is somewhere right around 7. This mildness makes dish soap perfect for day to day cleaning. Most surfaces won't be damaged by dish soap, and there are a lot of places it can be used besides in the kitchen sink

Explanation: I have had this question before

Answer:

7

Explanation:

Considering that you use dish soap on a daily occurence... it is best for it to be versatile. By making it 7... it is very neutral.

This means it's not too acidic for some situations... nor is it too basic in other situations.

Answer: 142.8%

Explanation:

13.8g H2 * (1 mol H2 / 2 g H2) * (2 mol H2O/ 2 mol H2) * (18 g H2O/1 mol H2O) = 124.2 g H2O

we just calculated our theoretical amount that should be formed and we are given the actual

percent yield: actual/theo * 100% = 124.2/87 * 100% = 142.8%

Answer: The results of the experimental observations should coincide with the facts of the current theories.

Explanation:

The scientific theory can be defined as the well defined as supported explanation for a natural phenomena. It is based upon the facts observed and also supported by the evidences obtained from the experimental trials.

If the experimental observations do not match with the concept of current scientific theory then the scientific either perform the experiment with the same scientific methodology or can switch to another scientific methodology to satisfy the facts of the current theories.

Percent yield = 70%

Percent yield is the comparison of the amount of product obtained from a reaction with the amount you calculated

General formula:

Percent yield = (Actual yield / theoretical yield )x 100%

An actual yield is the amount of product actually produced by the reaction. A theoretical yield is the amount of product that you calculate from the reaction equation according to the product and reactant coefficients

Reaction

2H₂ (g) + O₂ (g) → 2H₂O (g)

[tex]\tt mass=mol\times MW(mol~ratio~H_2O\div H_2=2\div 2)\\\\mass=(\dfrac{2}{2}\times \dfrac{13.8}{2})\times 18~g/mol\\\\mass=124.2~g[/tex]

[tex]\tt \%yield=\dfrac{87}{124.2}\times 100\%=\boxed{\bold{70\%}}[/tex]

Answer:

Gallium - Phosphorous - Fluorine - Chlorine

Explanation:

Answer:

Gallium < Phosphorus < Chlorine < Fluorine

Explanation:

<3