M = 4 g = 4/1000 kg = 0.004 kg, θ₂ = 21.0°C, θ₁ = 0°C , c = 0.44kJ/kg°C,
Q = mc(θ₂ - θ₁)
Q = 0.004*0.440*(21 - 0)
Q = 0.03696 kJ
0.03696 kJ<span> of heat is absorbed.</span>
Answer:
2gcm⁻³
Explanation:
Given parameters:
Mass of the object = 20g
Volume = 10mL
Unknown:
Density of the object = ?
Solution:
Density of a body is its mass per unit volume;
Density = 
We need to convert mL to cm³ for the volume
1mL = 1cm³;
10mL is therefore, 10cm³
So;
Density = 
= 2gcm⁻³
<span>We can use rocks to determine if the animals from to day have changed from the past.
Rocks also help us know if rivers once flowed through an area.
We use them to find out what type of animals live then that are extinct now.</span>
Answer:
20ppm
Explanation:
parts per million are defined as the mass of solute in mg (In this case, mass of DDT) per kg of sample.
To solve this question we must find the mass of DDT in mg and the mass of sample in kg:
<em>Mass DDT:</em>
0.10g * (1000mg / 1g) = 100mg
<em>Mass sample:</em>
5000g * (1kg / 1000g) = 5kg
Parts per Million:
100mg / 5kg =
<h3>20ppm</h3>
All of the the answers are are correct but a fume hood is more for if you are dealing with chemicals that can produce fumes the are deadly to people
