Chemistry

Since an element always has a different number of protons, the mass can indicate how many protons are in an isotope. TRUE FALSE

What is the value of the gas constant R, in units of $\frac {L-atm}{mol\cdot K}$ ? Report the value with at least three significant figures. Type answer: $\square $

Which equation is correctly balanced? $2K+Br2\rightarrow 2KBr$ $K+Br2\rightarrow 2KBr$ $2K+2Br2\rightarrow 2KBr$ $K+2Br2\rightarrow 2KBr$

Elements that form diatomic molecules include __

How many different types of subshells are there? 1(s) $5(s,p,d,f,z)$ $4(s,p,d,f)$ $3(s,p,d)$

Choose the formula for phosphate. a $PO_{4}^{3-}$ b $PO_{4}$ c $HPO_{4}^{2-}$

25. Write the Lewis structure for each element. (a) I (b) S (c) Ge (d) Ca

In art class students are mixing black and white paint to make gray paint. Sarah mixes 4 cups of black paint and 1 cup of white paint. Kayden mixes 5 cups of black paint and 2 cups of white paint. Use Sarah's and Kayden's percent of black paint to determine whose gray paint will be darker. Answer Attemptiout of 5 $Sarah's\quad percent\quad of\quad black\quad paint\quad (to\quad nearest\quad whole\quad number)=\square \% $ $Kayden's\quad percent\quad of\quad black\quad paint\quad (to\quad nearest\quad whole\quad number)=\square \% $ Sarah's gray paint will be darker. Kayden's gray paint will be darker. The two gray paints will be equally dark.

The electron configuration of nitrogen (N) is $1s^{2}2s^{2}2p^{3}$ th $1s^{2}2s^{2}2p^{4}$ $1s^{2}2s^{2}2p^{5}$ $1s^{2}2s^{2}2p^{6}$

How many valence electrons does lithium (Li) have available for bonding? 12 12 14