Answer: C) Elements and pure compounds are homogeneous materials because they have a uniform composition throughout.
Explanation: Element is a pure substance which is composed of atoms of similar elements. Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.
Elements are compounds form homogeneous materials as they have uniform composition throughout and the components are evenly distributed throughout the material.
Mixtures are heterogeneous materials as they do not have uniform composition and the components are not evenly distributed throughout the material.
Answer:
119.5 J
Explanation:
First we <u>calculate the temperature difference</u>:
- ΔT = 100 °C - 50 °C = 50 °C
Then we can <u>calculate the heat released</u> by using the following formula:
Where q is the heat, Cp is the specific heat, ΔT is the temperature difference and m is the mass.
We <u>input the data</u>:
- q = 0.239 J/g°C * 50 °C * 10.0 g
Answer:
Explanation:
An element whose atomic number is 68 (number Z), has 68 electrons and 68 protons. According to the periodic table it corresponds to the element Erbium (Er), whose mass number (A) is 167. The number of neutrons is 167-68 = 99.
Answer:
B.
Explanation:
ive done this before trust
