Which element has a melting point of -157°c

Answer:I think it’s mechanical energy

Explanation:

Answer:

Its can affect the safety of products by, for example, if you put raw chicken in the oven and don't cook it for long enough, it can make you sick

Explanation:

The difference between the calculated and precise worth is referred to as an error or defect. For example, if the two machinists use the same device to detect measurement mistakes, it is not necessary that they obtain the same results. However, there will be a little difference between the two measurements, which is referred to as an error.

Answer:

i think false

Explanation:

Centre of mass is the point at which the distribution of mass is equal in all directions, and does not depend on gravitational field. Centre of gravity is the point at which the distribution of weight is equal in all directions, and does depend on gravitational field

found it on google so it could be wrong

Answer:

True

Explanation:

I took a quiz and got it right

pls mark as brainliest.

Answer:

[tex]2.13\%[/tex]

Explanation:

Quantity of copper measured by a student = 4.6 grams

Original quantity of copper = 4.7 grams

Error in measurement = Original quantity of copper - Quantity of copper measured by a student  [tex]=4.7-4.6=0.1[/tex] grams

To find the percent error, apply the following formula:

Percent error = (Error in measurement / Original quantity of copper) × 100

[tex]=\frac{0.1}{4.7}(100)=2.13\%[/tex]

Answer:

with there wings

Explanation:

birds have wings that flap up and down when they fly and this process repeats over and over

Answer:

a )0.05 moles of O₂

b) 1.1207 dm³

c) 0.3× 10²³ atoms of oxygen

d) 1.6 g

Explanation:

Given data:

Number of molecules of O₂ = 3.01 × 10²² molecules

Number of moles of O₂ = ?

Volume of oxygen at ATP = ?

Number of oxygen atoms = ?

Mass of oxygen = ?

Solution:

The given problem will solve by using Avogadro number.

"It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance".  The number 6.022 × 10²³ is called Avogadro number.

Moles of oxygen:

1 mole = 6.022 × 10²³  molecules

3.01 × 10²² molecules  × 1 mol  / 6.022 × 10²³  molecules

0.05 moles of O₂

Number of atoms of oxygen:

1 mole = 6.022 × 10²³ atoms

0.05 mol × 6.022 × 10²³ atoms /1 mol

0.3× 10²³ atoms of oxygen

Volume of oxygen:

1 mole of oxygen at STP occupy 22.414 dm³

0.05 mol × 22.414 dm³ / 1mol

1.1207 dm³

Mass of oxygen:

Mass = number of moles × molar mass

Mass = 0.05 mol  × 32 g/mol

Mass = 1.6 g

Answer:

If you change everything at once, you may not know what caused the end result.

Explanation:

If you have Variable A (Salt), Variable B (Potassium), and the Control of Water, you might mix everything together, so you mix salt, potassium and water together. It is known that Potassium reacts very aggressively in water, but since you mixed everything together, you might think that salt+potassium+water goes boom, while it is actually potassium+water=boom.

Answer:

Unbalanced

Explanation:

The balanced equation would be:

C3H8 +  5  O2  --->  4  H2O +  3   CO2

Answer:

C. Biotechnology

Explanation:

In its broadest definition, biotechnology is the application of biological techniques and engineered organisms to make products or modify plants and animals to carry desired traits. This definition also extends to the use of various human cells and other body parts to produce desirable products.

The % lithium by mass in a sample of pure lithium carbonate : 18.79%

Proust states the Comparative Law that compounds are formed from elements with the same Mass Comparison so that compounds have a fixed composition of elements

% Lithium (Li) in Li₂CO₃(lithium carbonate) will remain the same even if the mass amount of Li₂CO₃ changes

Ar of Li = 6.941 g/mol

MW of  Li₂CO₃  = 73.891 g/mol

[tex]\tt \%Li=\dfrac{2.Ar~Li}{MW~Li_2CO_3}\times 100\%\\\\\5Li=\dfrac{2\times 6.941}{73.891} \times 100\%=18.79\%[/tex]

The quote; “Heisenberg may have slept here.” is used to show a situation that involves uncertainty.

The quote; “Heisenberg may have slept here.” is used to connote uncertainty. Recall that Heisenberg the German scientist is the famous inventor of the uncertainty principle.

Hence, the quote; “Heisenberg may have slept here.” is used to show a situation that involves uncertainty.

Learn more about uncertainty principle:https://brainly.com/question/1851822

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Volume displaced by jewelry, V = 278 - 200 = 78 ml

Also, 1 ml = 1 cm³

We know, by water displacement method the volume of water displaced by an object it equals to its own volume.

So, volume of jewelry, V = 78 ml = 78 cm³.

Also, weight of jewelry is , w = 122 gm.

Now, we know density is given by :

[tex]d=\dfrac{w}{V}\\\\d=\dfrac{122\ gm}{78\ cm^3}\\\\d=1.56\ gm/ cm^3[/tex]

Hence, this is the required solution.

Answer:

C. The mass of an electron is much less than the mass of a proton or

a neutron.

Explanation:

When we compare the mass of an electron to that of proton or neutron, the mass of an electron is much less than the mass of a proton or a neutron.

Electrons are negatively charged particles in an atom

Protons are positively charged particles

Neutrons do not carry any charges.

We can see that electrons have very small mass and this is why when calculating the mass of an atom, we use the sum of the number of protons and neutrons.

Answer:

I think it's replacement because the B and D just swap places in the end equation

Answer:

that would be replacment

Explanation:

if you look at the formula the B and D are replaced with each other

synthesis is when it looks like A+B--> AB

decompositions looks like AB--> A+B

and oxydation is when the states of atoms are changed so it would include things like +1, -1 etc

Answer:

Chemical reaction involved is:

CaCO

3

→CaO+CO

2

Molar mass of CaCO

3

=40+12+16×3=100 g

According to the balanced reaction 100 g of CaCO

3

produces 1 mol of CO

2

i.e. 22.4 L at STP.

∴50 g CaCO

3

will produce

100

22.4

×50=11.2 L CO

2

at STP.

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Considering the reaction stoichiometry, from the balanced equation and reation stoichiometry, the number of moles of calcium  oxide produced is 1 mole.

Chemical reactions are characterized by the appearance of new substances from others. That is, they are processes in which the nature of the substances changes, that is, from some initial substances called reagents, totally different ones called products are obtained.

In this case, you know that the balanced reaction is:

CaCO₃ → CaO + CO₂

Stoichiometry establishes relationships between the molecules or elements that make up the reactants of a chemical equation with the products of said reaction. In other words, stoichiometry determines the ratios between reactants and products in a chemical reaction.

The stoichiometry of a chemical reaction is perfectly established by the chemical equation. In it, the formulas of reactants and products appear preceded by numbers (the stoichiometric coefficients) that indicate the proportions according to which the transformation occurs.

The stoichiometric coefficients of a chemical equation are due to the fact that the atoms present before the reaction must be the same after the reaction, even though the atoms will have been rearranged to produce new substances.

In this case, by reaction stoichiometry, the following amounts of moles of each compound participate in the reaction:

In summary, from the balanced equation and reation stoichiometry, the number of moles of calcium  oxide produced is 1 mole.

Learn more:

Answer:

Its B. The atoms form a bond with a bond lenth of 75 pm

Answer:

x = 63

z = 117

x + z = 180

Explanation:

edg 2020

Answer:

Explanation:

c

Answer:

A. water H2O, everything else is a single element C,Fe&Cu

Explanation:

Answer:

a = 6 m/s².

Explanation:

If we have the object with mass of 75 kg and force on it is 50 N then according to given statement its acceleration is 3m/s².

When we double the force on same object by keeping the mass constant then the acceleration will also double. It means force will be 100 N and acceleration will be 6 m/s².

But if we we increase the mass then acceleration goes to decrease.

So,

mass = 75 kg

F = 50 N

a = 3m/s²  then by double the amount of force,

mass = 75 g

F = 100 n

a = 6 m/s².

This is actually explain the newton second law. This law stated that the acceleration of object is depend upon its mass and force acting on it.

F=  m. a

a = F/m

Thus acceleration is directly proportional to the force and inversely  proportional to the mass.

They're made up of three main parts: protons, neutrons and electrons. Think of the protons and neutrons as together forming a “sun”, or nucleus, at the centre of the system. The electrons orbit this nucleus, like planets. If atoms are impossibly small, these subatomic particles are even more so.

Answer:

mail carrier

Explanation:

Answer:

By just counting sigma bond and lone pair in central atom , one can easily find hybridization.

CO2 sp

SO2 sp2

NH3 sp3

BCl3 sp2

Answer:

Look in the picture

Explanation:

Answer:

its a Double Displacement (Metathesis) reaction

the balanced equation is 3AgNO3 + K3PO4 → Ag3PO4 + 3KNO3

Explanation:

Answer:

B

Explanation:

PE=m*delta(h)*g

So 0.75*1.5*9.8 equals PE

=11.025 so round up

Answer:

3+(10G)=DG

ER_K5(O5G)+29K

Answer

1.60217662 × 10-19 coulombs

Explanation:

.