Answer:
Their vibrations speed up
Explanation:
They start vibrating faster and faster and start generating more and more heat and separate from each other so, therefore (usually), become less dense
Answer: The correct option is 
Explanation:
Atomic mass of calcium ,Ca = 40.07 g/mol
Atomic mass of chlorine ,Cl = 35.5 g/mol
Molar mass of 
:
= (Atomic mass of Ca+2 × (Atomic mass of Cl))
= (40.07 g/mol + (2 × 35.5))=111.07 g/mol
Hence, the correct option is
Answer:
The repeating pattern of a mineral's particles form a solid called a <u>crystal</u>.
Explanation:
Answer:
A: Cellulose
Explanation:
Cellulose in paper and tree
Answer:
Elements: F, Cl, Br, I, At
Explanation:
Hi there,
When you are trying to find the valence electrons for an element, look at the last number of the electron configuration.
For example, if you want to find the number of valence electrons of Carbon (C), you notice that the electron configuration is<u> 2 - 4.</u>
We know that this element has four valence electrons because the last number in its electron configuration is 4.
For your question, simply find all of the elements that have the number 7 as the last number on its electron configuration on the periodic table.
Hope this answer was helpful. Cheers.
