4. The half-life for a 100-gram sample of radioactive element X is 5 days. How much of element X remains after 10 days have passed?
A. 25 g
B. 50 g
C. 75 g
D. 100 g

Answer:

the radius of sulfur is smaller than the radius of phosphorous. This is because atomic radius tends to decrease as you go left to right across the periodic table. Because sulfur is farther right than phosphorous is, it has a a smaller radius.

Explanation:

hope this helps :)

Answer:

D.

Explanation:

Translation:

A. make a barbecue

B. organize a picnic

C. swimming in the pool

D. to go skiing

Barbecue is usually a summer activity, so we eliminate that.

It would be too cold for a picnic!

It would be too cold to go swimming, and that's more of a summer thing!

Skiing is a snow activity, and since it is winter, it is likely to know.

Answer:

I hope this helps

Explanation:

Lewis symbols, which are also known as Lewis dot diagrams or electron dot diagrams, are diagrams that represent the valence electrons of an atom. Lewis structures, also known as Lewis dot structures or electron dot structures, are diagrams that represent the valence electrons of atoms within a molecule.

Answer:

E = 45.08×10⁻¹⁹j

Explanation:

Given data:

Energy of photon  in joule = ?

Frequency of photon = 6.8×10¹⁵ Hz

Solution:

Formula:

E = h.f

f = frequency

h = planck's constant (6.63×10⁻³⁴Js)

E = energy

Value of planck's constant is 6.63×10⁻³⁴Js.

E = 6.63×10⁻³⁴Js ×6.8×10¹⁵  Hz

Hz = s⁻¹

E = 6.63×10⁻³⁴Js ×6.8×10¹⁵  s⁻¹

E = 45.08×10⁻¹⁹j

Energy is the quantitative unit, which is measured in joules. The energy of a photon of UV light having the frequency  6.8×10¹⁵ Hz is 45.08×10⁻¹⁹ Joules.

Given:

Frequency of photon = 6.8×10¹⁵ Hz

Energy of a photon in joule =?

Usingt the formula of energy:

E = h x v

where,

v = frequency

h = planck's constant (6.63×10⁻³⁴Js)

E = energy

Substituting the values in the equation, we get:

E = 6.63×10⁻³⁴Js ×6.8×10¹⁵ Hz

E = 6.63×10⁻³⁴Js ×6.8×10¹⁵ s⁻¹

E = 45.08×10⁻¹⁹ Joules

Therefore, the energy of a photon in the UV region is 45.08×10⁻¹⁹ Joules

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Answer:

A wave reflection interaction (reflected by the wall)

Explanation:

In a reflection, the propagating wave is bounced off the reflecting surface because the medium of the surface prevents the propagation of the wave through it, such that wave is redirected at an angle equal to the angle of incident on the reflecting surface

Reflection takes place with the different forms of waves, such as sound wave, water waves, and light wave

The objects around us are seen with the aid of reflection of light from a light source such that the reflected light enters our eyes after being reflected on the surface of the object, and the object is seen.

Answer:

reflection

Explanation:

its on edg.

Answer:

Your answer is D (gain enough kinetic energy to get past each other.)

Explanation:

Melting can be best described as a process in which molecules gain enough kinetic energy to get past each other and the correct option is option D.

Melting is the process by which a substance changes from the solid phase to the liquid phase. Melting is also known as fusion, although this term has several meanings in science.

Melting occurs when the kinetic energy of a solid increases by application of heat or pressure, such that the molecules of solid start vibrating faster but stay close to their neighboring particles, rolling around each other. This particle movement allows the substance to flow and form a liquid.

Therefore, melting can be best described as a process in which molecules gain enough kinetic energy to get past each other and the correct option is option D.

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Answer:

Don't mark me brainliest because of this but I'm pretty sure your supposed to give us the words because teachers don't give you things like that without the words you will the answer in with.

Answer:

Same as number of NUETRONS

POSITIVE charge

number of protons is the same as the atomic NUMBER

Located in the Nucleus

Larger mass than ELECTRONS

Explanation:

GOOD LUCK

Answer:

An electromagnet is a coil of wire wrapped around a bar of iron or other ferromagnetic material. When electric current flows through the wire, it causes the coil and iron bar to become magnetized. An electromagnet has north and south magnetic poles and a magnetic field.

Explanation:

The three main components of an electromagnet are the iron core, copper wire, and an electricity source.

An electromagnet is a magnet in which a coiled or wrapped wire is given electricity. When Current is given to this wire, it acts like a magnet. An electromagnet is used to create a magnetic field.

The three main parts of the electromagnet are the iron core, that is the magnet, which is a small round, or square brick-like. The wire, wire, is made up of copper. The electricity source, by which electricity is given to the electromagnet.

Examples of electromagnets are induction cookers, doorbell rings, etc. They are controllable and adjustable magnets and are used in most electric appliances.

Thus, the three parts are the iron core, copper wire, and an electricity source.

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Answer:

because it is a theory

Explanation:

The best explanation for why scientific theories are modified is simply because it is a theory. Theories are created as a set of suppositions that help humanity understand something that would otherwise be unexplainable. Since they are not proven through scientific facts but instead are more of ideas that help further our understanding of a phenomenon, they tend to be modified as new ideas are introduced and others are proven to be false/wrong.

Answer:

Liquid

Explanation:

The substance had appears to have a fixed volume but took the shape of the bottle it was transferred to.

If the substance doesn't have the same volume, the answer would be gas.

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:

1. Write the symbol and charge of the cation (metal) first and the anion (nonmetal) second. 2. Transpose only the number of the positive charge to become the subscript of the anion and the number only of the negative charge to become the subscript of the cation

Name: Cerium

Symbol: Ce

Atomic Number: 58

Atomic Mass: 140.116 amu

Number of Protons/Electrons: 58

Number of Neutrons: 82

Answer:

The answer is

[tex] \huge 4\%[/tex]

Explanation:

The percentage error of a certain measurement can be found by using the formula

[tex]P(\%) = \frac{error}{actual \: \: number} \times 100\% \\ [/tex]

From the question

actual mass = 6.25 g

error = 6.25 - 6 = 0.25

So we have

[tex]p(\%) = \frac{0.25}{6.25} \times 100[/tex]

We have the final answer as

Hope this helps you

Given parameters:

Density of table salt = 2.16g/cm³

Mass of table salt  = 4.25kg = [tex]\frac{0.00425}{2.16}[/tex][tex]\frac{0.00425}{2.16}[/tex]g (1000g = 1kg)

Unknown:

Volume of table salt = ?

Solution:

To find the volume of the table salt, let us state the relationship between density, mass and volume.

 Density is the mass per unit volume of substance.

           Density  = [tex]\frac{mass}{volume}[/tex]  

Since the unknown is volume;

      Density x volume  = mass

                    Volume  = [tex]\frac{mass}{density}[/tex]

Input the parameters and solve';

                  Volume  = [tex]\frac{0.000425}{2.16}[/tex]  = 1.97 x 10⁻³cm³

Volume of the table salt is  1.97 x 10⁻³cm³

Answer:

Whats the question lolzzzz

Explanation:

Answer:

9.876

Explanation:

Answer:

that's so easy but if you still need the answer i am willing to help

Explanation:

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:

They were formed right after the "Big Bang" when our known universe originated from pure energy some billions of years ago. The energy was converted to the elementary particles (quarks, gluons, leptons etc...) from which protons and neutrons were formed. From these, atoms of different elements were produced

Answer :The reason why compression is more difficult is a direct illustration of quantum mechanics.

Answer:

The number of electrons in a neutral atom is equal to the number of protons. The mass number of the atom (M) is equal to the sum of the number of protons and neutrons in the nucleus. The number of neutrons is equal to the difference between the mass number of the atom (M) and the atomic number (Z).

Explanation:

Answer:

Substance

Explanation:

Answer: Substance

Explanation:Ex: Hydrogen gas is a pure substance, as it is made up of only Hydrogen atoms or molecules. Carbon, gold, & nitrogen are other elements (pure substances).

Answer:

Its a mixture.