Answer:
British chemist John Newlands was the first to arrange the elements into a periodic table with increasing order of atomic masses. He found that every eight elements had similar properties and called this the law of octaves. He arranged the elements in eight groups but left no gaps for undiscovered elements.
How does mercury negatively affect human health?
Answer:
The inhalation of mercury vapour can produce harmful effects on the nervous, digestive and immune systems, lungs and kidneys, and may be fata
Explanation:
Write the reaction to prepare C2H5Br from (image attached)
a) alcohol using PX3
b) Alcohol using HX
The equations for the preparation of C₂H₅Br from alcohol using PX₃ and HX are shown in the attachment below.
a) Preparation of C₂H₅Br from alcohol using PX₃
In PX₃, X refers to the halides (F, Cl, Br etc.). Since the desired ethyl halide is ethyl bromide (C₂H₅Br) , then X in PX₃ will be Br. Therefore, PBr₃ will be used in the reaction as shown in the attachment below.
b) Preparation of C₂H₅Br from alcohol using HX
Also, In HX, X refers to the halides (F, Cl, Br etc.). Since the desired ethyl halide is ethyl bromide (C₂H₅Br), then X in HX will be Br. Therefore, HBr will be used in the reaction as shown in the attachment below.
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How many moles of molecules and atoms are in 3.07g sample of SO3
Molecules____
Atoms_______
Answer:
ammonia molecules. Similar factors may be derived for any pair of substances in any chemical equation. Example 4.8. Moles of Reactant Required in a Reaction.
Explanation:
100g of radioactive mass has a half life of 5 days. Calculate the mass decayed off after 15 days
Answer:
12.5 gm
Explanation:
15 days is three half lives
100 * (1/2)^3 = 12.5 grams
The neutrons affect the stability of the nucleus of the atom. True or False
Answer:
True.
Explanation:
This is because when the number of protons in the nucleus increases the neutrons needed for a stable nucleus increases even more rapidly.
Best of luck!!!
A 147g piece of metal has a density of 7.00g/mL. A 50mL graduated cylinder contains 20.0mL of water. What is the final volume after the metal is added to the graduated cylinder
Answer: 41.0 ml
Explanation: (147g/7.00g/ml) = 21.0 ml for the metal
Add to 20.0ml to reach 41.0 ml to 3 sig figs
Define the following terms:
-hypothesis:
- theroy:
-law:
Answer:
hypothesis = A tentative explanation for a question, testable through experiments.
theory = An explanation supported by many experiments, answers "why".
law = A relationship in nature supported by many experiments.
Explanation:
Help me with physical science
Answer:ok
Explanation:fish
When sodium reacts with Iron(II)and chloride iron metal and sodium chloride are formed what are the coefficient used in this reaction?
A loud sound has a large
Answer:
This extra energy causes the string to vibrate more, which helps it move more air particles for a longer time. A string plucked with force has greater amplitude, and greater amplitude makes the sound louder when it reaches your ear. Volume depends on amplitude. Greater amplitude produces louder sounds.
What is the number of nitrogen molecules in 6.0 moles of N2?
Explanation:
just take the given moles and multiply it with the ratio of molecules to moles to get your answer
The number of nitrogen molecules in 6.0 moles of N2 is = 3.6 × 10²⁴
How to calculate number of moleculesAvogadro's number( 6.02 × 10²³) is equal to the number of molecules in 1 mole of substance.
That is,
1 mole of N2 = 6.02 × 10²³
6 moles of N2 = 6 × 6.02 × 10²³
= 36.12 × 10²³
= 3.6 × 10²⁴
Therefore, the number of nitrogen molecules in 6.0 moles of N2 is = 3.6 × 10²⁴
Learn more about molecules here:
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What happens to the carbon in natural gas when the gas burns in a badly fitted gas fire? Explain your answer
Explanation:
Fuels such as natural gas and petrol contain hydrocarbons. These are compounds of hydrogen and carbon only. When they burn completely: the carbon oxidises to carbon dioxide
A student carrying a glass cup trips and drops the glass, then it shatters.
What type of change is this?
A. Physical change
B. Chemical change
C. Mixture change
(Need explanation too)
Answer:
A
Explanation:
Answer:
A is the correct answer I believe
Could someone help me please?
Answer:
I think its A And C OR D HOPE ITS RIGHT
Explanation: BY THE LOVE YOUR AVTAR
True statements are:
Density increases if the volume of an object decreases and the mass remains the same.
Density increases if the mass of an object increases and the volume remains the same.
Density remains the the same if the mass and volume of an object increases proportional.
Further:
Density = Mass/Volume
777,600 seconds to days
Answer:
9 days
No explanation needed.
Please help it’s worth a lot!! I need the answer ASAP!!
Answer:
Show me the previous question so I can help
When potassium is added to water, what causes the explosion?
Answer:
The highly unstable pure sodium or potassium wants to lose an electron, and this splits the water atom, producing a negatively charged hydroxide ion and hydrogen and forming an explosive gas that ignites.
Explanation:
Compound 2 contains 2.0g of hydrogen and 32.0g oxygen. What is the percent compound of each element?
Note down the formula below
[tex]\boxed{\sf Mass\%\;of\; element=\dfrac{Mass\:of\:the\: element}{Mass\;of\:the\: compound}\times 100}[/tex]
Mass of the compound
[tex]\\ \sf\longmapsto 32+2=34g[/tex]
Mass % of Hydrogen:-
[tex]\\ \sf\longmapsto \dfrac{2}{34}\times 100[/tex]
[tex]\\ \sf\longmapsto \dfrac{1}{17}\times 100[/tex]
[tex]\\ \sf\longmapsto 5.8\%[/tex]
Mass % of Oxygen:-
[tex]\\ \sf\longmapsto \dfrac{32}{34}\times 100[/tex]
[tex]\\ \sf\longmapsto \dfrac{16}{17}\times 100[/tex]
[tex]\\ \sf\longmapsto 94.2\%[/tex]
1. What is Science?
A. The goal of science is to investigate and understand the natural world, to explain events in the natural
world, and to use those explanations to make useful predictions.
PLS I NEED HELP
The distance from the Sun to Mercury is 3.598 • 10^7
miles. The distance from the Sun to Neptune is
2.798. 10^9 miles. How far is Mercury from Neptune?
Write your answer in scientific notation.
Answer:
4.44309 × 109 ( 4443090000 kilometres )
2.760936126 × 109 ( 2760936126 miles)
Please make me the brainliest! !!
Answer:
The distance of Mercury to Neptune = The distance from sun to Neptune - The distance from sun to Mercury
= 2.798 . 10^9 - 3.598 . 10^7
= 2.798 . 10^9 - 0.03598 . 10^9
= 10^9 ( 2.798 - 0.03598 )
= 2.76202 . 10^9 miles
.
.
Hope it helps
Match the event with the type of change.
a. Making ice cubes from water
b. Making hot water for tea
c. Using dry ice to create a foggy punch bowl
а
<
1. Changes Between Liquids and Solids
2. Changes Between Liquids and Gases
3. Changes Between Solids and Gases
a
<
av
Answer:
A-1,
B-2,
C-3 is the answer of this queation
what will happen to the atoms or molecules of a substance when it boils
Answer: It will change to gas
Explanation: It will change to gas because of evaporation. When the heat intensifies it will happen.
1. Is each of the following statements true or false? Correct any that are false.
a. A mole of one substance has the same number of atoms as a mole of any other substance
b. The theoretical yield for a reaction is based on the balanced chemical equation
c. A limiting reactant problem is being stated when the available quantity of one of the reactants is given in moles
d. The empirical and molecular formulas of a compound are always different.
Scientists have cited gas emission as contributing to global [blank] , which is a general increase in temperatures worldwide.
Answer:
Warming
Explanation: Greenhose gases (CO2, CH4, etc.) trap heat in Earth's atmosphere since they absorb wavelenghts of light associated with heat.
arlon drank 500 mL of softdrink which had a mass of 450 g.
a. 1.11 g/mL c. 0.9 g/mL
b. 50 g/mL d. 225000 g/mL
Answer:
0.9 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]d = \frac{m}{v} \\ [/tex]
where
m is the mass
v is the volume of object
From the question we have
m = 450 g
v = 500 ml
[tex]d = \frac{450}{500} = \frac{9}{10} \\ = 0.9[/tex]
We have the final answer as
0.9 g/mLHope this helps you
Answer:
B) g/mL
Explanation:
Mass of Oxalic acid (solute) = 11g
Mass of Solution = 500ml
Density = 1.1 g/ml
We know that
Mass % of solute =
Massofsolution
Massofsolute×100
×
50
Mass of solution =
Volume of solution×
Density of solution
Mass of solution =
500×
1.1=
50×
11g
Mass % of the solute =
11×50
11×100
=
2%
How many grams are there in 6 moles of water, full working out?
1 mole of water = 18g
6 moles of water = 18×6 = 108 g
Why is sodium a significant source of calories in both foods
Answer: Sodium is made up of lots of salt.
Explanation:
Eating a lot of salt can cause your body to retain more water, which can show up on the scale as extra pounds. But we're not just talking about water weight here. High salt diets appear to be linked to higher body fat in particular, the kind of fat that accumulates around your middle.
Employers may not fire or other wise discriminate against an employee who does which of the following
Answer:
race, religion, sex, if they are 40 or older, have a disability, pregnancy/childbirth. hope that helped
What are three properties of inertia?
what does it mean when a reaction has a negative amount of Kj
Answer:
heat is released in going from reactants to products
Explanation:
hope this helps
