hi can someone help me with these 2 :)

Answer:

If the pH of a solution is less than 7, the solution is called acidic; if the pH is about 7, the solution is neutral; if the pH is greater than 7, the solution is is called basic. In an acidic solution, then, the concentration of hydrogen ions is greater than the concentration of hydroxide ions.

Explanation:

Not sure about the context of the question, but you can check with a ph scale tester.

Answer:

Easy 46 million turkeys

Medium three days

Hard: 1934

Fun: The first President on record issuing a "pardon" to his turkey was Ronald Reagan.

Explanation:

hop tis helped

Answer:

I think it is chemical change

Answer:

CH4 + 2 O2 → CO2 + 2 H2O

Explanation:

There are one mole of O2 on the left side and on the right side there are three moles of O2. And to fix it you would need to make it two moles of O2 to have four molecules of O2 on the left side. Then you would make two moles of H2O to have a total of four moles of O2 on the right. Therefore, CH4 + 2 O2 → CO2 + 2 H2O is the answer.

Answer:

1,2,1,2

Explanation:

hope this helped!

Answer:

The answer is that light is faster than sound.

Explanation:

A good example is of lightning and thunder during a thunderstorm.

mark me brainliest!

Explanation:

element with atomic numbers 7 and 83 have 5 and 5 valence electrons

Answer:

5 moles of oxygen occupy 120 dm³ volume.

Explanation:

Given data:

Number of moles = 5 mol

Volume of gas = ?

Solution:

In question it is given gas is at room temperature and pressure.

One mole of any gas at room room temperature and pressure occupy volume of 24 dm³. Thus,

5 mole of gas occupy volume of,

5 mol × 24 dm³/1 mol

120 dm³

5 moles of oxygen occupy 120 dm³ volume.

Answer:

67.6 years is the time the isotope take to decay from 0.900g to 0.170g

Explanation:

The radioactive decay follows first order law:

Ln [A] = -kt + ln[A]₀

Where [A] is concentration after time t,

k is decay constant:

k = ln 2 / t(1/2)

k = ln2 / 28.1 years

k = 0.02467 years⁻¹

[A]₀ = Initial concentration.

We can replace concentration and use the mass of the isotope:

Ln [A] = -kt + ln[A]₀

Ln [0.170g] = -0.02467 years⁻¹t + ln[0.900g]

-1.667 = -0.02467 years⁻¹t

t =

The time required for the sample to reduce to 0.170 grams has been 67.75 years.

Half-life can be defined as the times required by the substance to reduce to half of its initial concentration.

The half-life can be expressed as:

Amount left = Initial amount [tex]\times[/tex] [tex]\rm \dfrac{1}{2}^\dfrac{time}{Half-life}[/tex]

From the given:

0.17 g = 0.9 [tex]\rm \times\;\dfrac{1}{2}^\dfrac{t}{28.1}[/tex]

[tex]\rm \dfrac{0.17}{0.9}[/tex] = [tex]\rm \dfrac{1}{2}^\dfrac{t}{28.1}[/tex]

0.188 = [tex]\rm (0.5)^\dfrac{t}{28.1}[/tex]

Taking log on both the sides,

log 0.188 = [tex]\rm \dfrac{t}{28.1}\;\times[/tex] log 0.5

2.411 = [tex]\rm\dfrac{t}{28.1}[/tex]

t = 2.411 [tex]\times[/tex] 28.1 years

Time = 67.75 years.

The time required for the sample to reduce to 0.170 grams has been 67.75 years.

For more information about half-life, refer to the link:

https://brainly.com/question/24710827

Answer:

Viscosity

Explanation:

The viscosity of the liquid is the independent variable. The flow rate is the dependent variable in this hypothesis.

The statement given is called the hypothesis. It is a form of scientific guess into a phenomenon.

Answer:

Explanation:

The mass of a substance when given the density and volume can be found by using the formula

mass = Density × volume

From the question we have

mass = 0.917 × 2.5 = 2.2925

We have the final answer as

Hope this helps you

Answer:. 2.3 g

Explanation:

Answer:

I think it might be:

NiO=2

CuO=4

BaO=2

Explanation:

Hope this helps.

Answer:

B

Explanation:

Answer:

B. Always add the acid to the water slowly, taking a moment to stir between drops

Answer:

2

Explanation:

Answer:

its eathe a or c a 50/50 chance

Answer:

Explanation:

its B

(please mark as brainliest if it's correct)

Answer:C - 3.115 g

Explanation:Correct

Explanation:

The halogen family and noble gases are similar in just one particular way, they are groups of non-metals. All members of these two groups are categorized as non-metals.

Here are some of the differences between them;

Answer:

125 cubic meters

Explanation:

Subtract 375-250=125 cubic meters

Answer:

hail, btw have a nice day

Answer:

Hail

Explanation:

I got it right on my test

The chemical formula for an ionic compound represents the simplest ratio of ions that results in an electrically neutral compound. That is option D.

An ionic chemical compound is defined as the type of chemical compound that contains both the oppositely-charged ions of a metal and a nonmetal are attracted reacting with each other to form an ionic bond.

When represented as a chemical formula, it is the simplest ratio of ions that results in an electrically neutral compound.

Learn more about ionic compound here:

https://brainly.com/question/28851190

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Answer:

Acid rain

Explanation:

The independent variable in the hypothesis statement is the acid rain. An independent variable is usually the cause in an experiment.

This variable give rises to the effects observed as the dependent variable.

In the presence of the acid rain, the fish population will increase.

The dependent variable is the fish population or number of fishes.

The independent variable is the acid rain as it is the cause of the effect observed on the fish population.

Answer:

answer is D

Explanation:

Answer:

Cobalt/Electron configuration

Explanation:

[Ar] 3d7 4s2

Answer: the molar mass will be too high

Explanation:

Answer:

liquid state is an intermediate phase between solid and gas phase

Answer is A. H20

Answer:

H2O

Explanation:

As H2 is a gas, and the question asks for the liquid state, it'd be H2O.

Answer:

True

Explanation:

All irreversible reactions go to completion because the process cannot proceed in the backward direction.

A reversible reaction is one that does not go into completion in one direction.

An irreversible direction completely uses up the reactants to form the products and goes into completion.

These reactions can only proceed in one direction and not both.

Answer:

3.1 moles of ammonia

18.67× 10²³ molecules

Mass = 52.7 g

Explanation:

Given data:

Number of atoms of hydrogen = 5.68×10²⁴ atoms

A) Number of molecules of ammonia = ?

Solution:

First of all we will calculate the number of moles of hydrogen.

1 mole = 6.022× 10²³ atoms

5.68×10²⁴ atoms × 1 mol / 6.022× 10²³ atoms

0.94×10¹ mol

9.4 moles of hydrogen

Moles of ammonia:

3 moles of hydrogen are present in one mole of ammonia.

9.4 moles of hydrogen = 1/3×9.4 =

3.1 moles of ammonia

Number of molecules of ammonia:

1 mole contain 6.022× 10²³ molecules.

3.1 mol × 6.022× 10²³ molecules / 1 mol

18.67× 10²³ molecules

c) Mass of sample = ?

Mass = number of moles × molar mass

Mass = 3.1 moles × 17 g/mol

Mass = 52.7 g

Answer:

beryllium has a higher ionization energy because its radius is smaller. boron has a higher ionization energy because its radius is smaller.