Answer:
The element is CARBON
The number 6 refers to the ATOMIC NUMBER
the numbers 12, 13, and 14 refer to the ATOMIC MASS
how many protons and neutrons are in the first isotope?
<u>6</u><u>. </u><u> </u><u> </u><u> </u><u> </u><u>6</u>
how many protons and neutrons are in the second isotope?
<u>6</u><u>. </u><u> </u><u> </u><u> </u><u> </u><u> </u><u>7</u>
<u>how many protons and neutrons are in the </u><u>t</u><u>h</u><u>i</u><u>r</u><u>d</u><u> </u><u>isotope?</u>
<u>6</u><u>. </u><u> </u><u> </u><u> </u><u> </u><u> </u><u> </u><u>8</u>
<u>y</u><u>o</u><u>u</u><u> </u><u>a</u><u>r</u><u>e</u><u> </u><u>w</u><u>e</u><u>l</u><u>c</u><u>o</u><u>m</u><u>e</u><u> </u><u>:</u><u>)</u>
Answer:
The time required to melt the frost is 3.25 hours.
Explanation:
The time required to melt the frost dependes on the latent heat of the frost and the amount of heat it is transfered by convection to the air .
The heat transferred per unit area can be expressed as:

being hc the convective heat transfer coefficient (2 Wm^-2K^-1) and ΔT the difference of temperature (20-0=20 °C or K).

If we take 1 m^2 of ice, with 2 mm of thickness, we have this volume

The mass of the frost can be estimated as

Then, the amount of heat needed to melt this surface (1 m²) of frost is

The time needed to melt the frost can be calculated as

If you start with 40.0 grams of the element at noon, 10.0 grams
radioactive element will be left at 2 p.m. The correct answer between
all the choices given is the second choice or letter B. I am hoping that this
answer has satisfied your query and it will be able to help you in your
endeavor, and if you would like, feel free to ask another question.
Answer:
I might next year with my cuz and nex year ima be in 8th
Explanation: