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3 years ago

Which of the following items are true of early nuclear science?

1 answer:

7 0

The items that are true of early nuclear science are "the first nuclear reactions were done in the 1880s" and "the first nucleus split was uranium-235." <span>The answers are letters A and D. It is impossible that nucleus was lost during the reaction as it will not follow the law of mass conservation.

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Which characteristic is a property of water

likoan [24]

It is made of polar molecules

8 0

2 years ago

A researcher studying the nutritional value of a new candy places a 4.70 g 4.70 g sample of the candy inside a bomb calorimeter

Sauron [17]

Answer : The nutritional Calories per gram of the candy are, 5.36 calories

Explanation :

First we have to calculate the amount of heat.

$q=c\times \Delta T$

where,

q = heat = ?

c = specific heat = $43.90kJ/K$

$\Delta T$ = change in temperature = $2.41^oC=2.41K$

Now put all the given values in the above formula, we get:

$q=43.90kJ/K\times 2.41K$

$q=105.799kJ$

Now we have to calculate the heat for per gram of sample.

Heat = $\frac{105.799kJ}{4.70g}=22.51kJ/g=22510J/g$

Now we have to calculate the heat in terms of calories.

As, 1 nutritional Calories = 1000 calories

and, 1 calories = 4.2 J

As, 4.2 J = 1 calories

So, 22510 J = $\frac{22510J}{4.2J}\times \frac{1}{1000}cal=5.36cal$

Therefore, the nutritional Calories per gram of the candy are, 5.36 calories

5 0

3 years ago

Metal carbonates decompose to the metal oxide and CO2 on heating according to this general equation. Mx(CO3)is) → My(s) + yCO2(g

Mrrafil [7]

Answer:

84.11 g/mol

Explanation:

A metal from group 2A will form the cation M²⁺, and the ion carbonate is CO₃²⁻, so the metal carbonate must be: MCO₃, and the reaction:

MCO₃(s) → MO(s) + CO₂(g)

For the stoichiometry of the reaction, 1 mol of MCO₃(s) will produce 1 mol of CO₂. Using the ideal gas law, it's possible to calculate the number of moles of CO₂:

PV = nRT , where P is the pressure, V is the volume(0.285 L), R is the gas constant (62.36 mmHg*L/mol*K), n is the number of moles, and T is the temperature (25 + 273 = 298 K).

69.8*0.285 = n*62.36*298

18583.28n = 19.893

n = 0.00107 mol

So, the number of moles of the metal carbonate is 0.00107. The molar mass is the mass divided by the number of moles:

0.0900/0.00107 = 84.11 g/mol

4 0

3 years ago

The density of a mixture measures 1030.5 kilograms per cubic meter. Use scientific notation to represent the density of the mixt

zzz [600]

The formula for density = mass/volume

So the units are gcm^3

So multiply by 1000 to get into grams - 1030500

Add units

1030500gcm^3

7 0

3 years ago

Read 2 more answers

An element has a mass of 207 and 125 neutrons in its nucleus. How many protons & electrons does it have & where are they

SashulF [63]

The number of protons can be calculated by subtracting 207 with 125

Therefore, proton no. : 207 - 125

= 32

Proton number and electron number is always equivalent, so there are 32 electrons in the electron shells

Protons and neutrons are always located in the nucleus of an atom, and electrons are located in the electron shells which always move rapidly around the atom

The element which is referred is Lead(Pb)

7 0

3 years ago