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3 years ago

Animals need food air and water.which of the following is another need of animals

Chemistry

2 answers:

Readme [11.4K]3 years ago

6 0

Answer:

a habitat

Explanation:

Law Incorporation [45]3 years ago

3 0

a sanctuary could be one of them

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Explain the working principle of a clinical thermometer

bagirrra123 [75]

Answer:

A clinical thermometer is a thermometer used to measure human body temperature. Most made in the 20th century are mercury-in-glass thermometers. They are accurate and sensitive, having a narrow place where the mercury level rises very fast. A kink in the tube stops the mercury level from falling on its own.

3 0

3 years ago

A galvanic (voltaic) cell consists of an electrode composed of nickel in a 1.0 M nickel(II) ion solution and another electrode c

Andre45 [30]

Answer: The standard potential of the cell is 0.77 V

Explanation:

We know that:

$E^o_{Ni^{2+}/Ni}=-0.25V\\E^o_{Cu^{+}/Cu}=0.52V$

The substance having highest positive $E^o$ reduction potential will always get reduced and will undergo reduction reaction.

The half reaction follows:

Oxidation half reaction: $Ni(s)\rightarrow Ni^{2+}(aq)+2e^-$

Reduction half reaction: $Cu^{+}(aq)+e^-\rightarrow Cu(s)$ ( × 2)

To calculate the $E^o_{cell}$ of the reaction, we use the equation:

$E^o_{cell}=E^o_{cathode}-E^o_{anode}$

Substance getting oxidized always act as anode and the one getting reduced always act as cathode.

Putting values in above equation follows:

$E^o_{cell}=0.52-(-0.25)=0.77V$

Hence, the standard potential of the cell is 0.77 V

5 0

3 years ago

A rock contains 0.623 mg of 206Pb for every 1.000 mg of 238U present. Assuming that no lead was originally present, that all the

maxonik [38]

Answer:

t = 3,496x10⁹ years

Explanation:

The decay of ²³⁸U is:

²³⁸U → ²⁰⁶Pb + 8He + 6e⁻

Moles of ²⁰⁶Pb presents in 0,623mg are:

0,623x10⁻³g×(1mol / 206g) = 3,02x10⁻⁶ moles of ²⁰⁶Pb.

These moles are equals to moles of ²³⁸U before decay, that means, 3,02x10⁻⁶ moles²³⁸U

In grams:

3,02x10⁻⁶ moles²³⁸U× (238g / 1mol) = 7,20x10⁻⁴ g ²³⁸U = 0,720 mg²³⁸U

That means initial ²³⁸U was 1,000mg + 0,720mg = 1,720mg

Applying the formula:

ln (N₀/N) t₁₂ = t ln2

Where N₀ is initial amount of uranium (1,720mg), N is concentration of uranium (1,000mg), half-life time is a constant (t₁₂= 4,468x10⁹ years) and t is the time transcurred for the reaction. Replacing:

ln(1,720/1)*4,468x10⁹ years = t ln2

t = 3,496x10⁹ years

I hope it helps!

6 0

2 years ago

During beta decay, a nucleus _________.. a. gains a proton and loses a neutron. b. gives up two protons and two neutrons. c. mai

Alexxandr [17]

Hello!

a. gains a proton and loses a neutron. This process gives more stability to the atom.

Hugs!

8 0

3 years ago

Which of the following correctly compares the uses of line graphs versus pie chart

larisa [96]

the line graphs and pie charts are used for different kinds of analysis

a) pie chart : it compares the portion of one thing in a group of different things

For example out of 100 people how many have brown hairs , how many have black hairs and how many have white hairs

like population division out of 100 into different parts

b) line graphs: they show the relation ship between two variables

Example: effect of temperature on volume

it tells the trend in any property with respect to some other quantity or quality parameter.

6 0

3 years ago

Read 2 more answers